Printing components to adhesive substrate posts

ABSTRACT

A method of printing comprises providing a component source wafer comprising components, a transfer device, and a patterned substrate. The patterned substrate comprises substrate posts that extend from a surface of the patterned substrate. Components are picked up from the component source wafer by adhering the components to the transfer device. One or more of the picked-up components are printed to the patterned substrate by disposing each of the one or more picked-up components onto one of the substrate posts, thereby providing one or more printed components in a printed structure.

CROSS REFERENCE TO RELATED APPLICATIONS

Reference is made to Attorney Docket No. 2011486-0746 filed Dec. 3,2018, entitled Printed Components on Substrate Posts, by Gomez et al.,to Attorney Docket No. 2011486-0747 filed Dec. 3, 2018, entitled ModuleStructures with Component on Substrate Post, by Rotzoll et al., toAttorney Docket No. 2011486-0748 filed Dec. 3, 2018, entitled PrintingComponents Over Substrate Post Edges, by Trindade et al., to AttorneyDocket No. 2011486-0755 filed Dec. 3, 2018, entitled Device Structureswith Acoustic Wave Transducers and Connection Posts, by Cok, to U.S.patent application Ser. No. 15/047,250, filed Feb. 18, 2016, entitledMicro-Transfer-Printed Acoustic Wave Filter Device, by Bower et al., andto U.S. patent application Ser. No. 15/639,495, filed Jun. 30, 2017,entitled Transverse Bulk Acoustic Wave Filter, by Bower et al., thecontents of each of which are incorporated by reference herein in theirentirety.

TECHNICAL FIELD

The present disclosure relates generally to printed or printablestructures including components and methods for disposing components onsubstrate posts of patterned substrates.

BACKGROUND

Substrates with electronically active components distributed over theextent of the substrate may be used in a variety of electronic systems,for example, in flat-panel display devices such as flat-panel liquidcrystal or organic light emitting diode (OLED) displays, in imagingsensors, and in flat-panel solar cells. The electronically activecomponents are typically either assembled on the substrate, for exampleusing individually packaged surface-mount integrated-circuit devices andpick-and-place tools, or by sputtering or spin coating a layer ofsemiconductor material on the substrate and then photolithographicallyprocessing the semiconductor material to form thin-film circuits on thesubstrate. Individually packaged integrated-circuit devices typicallyhave smaller transistors with higher performance than thin-film circuitsbut the packages are larger than can be desired for highly integratedsystems.

Other methods for transferring active components from one substrate toanother are described in U.S. Pat. No. 7,943,491. In an example of theseapproaches, small integrated circuits are formed on a nativesemiconductor source wafer. The small unpackaged integrated circuits, orchiplets, are released from the native source wafer by etching a layerformed beneath the circuits. A viscoelastic stamp is pressed against thenative source wafer and the process side of the chiplets is adhered toindividual stamp posts. The chiplets on the stamp are then pressedagainst a destination substrate or backplane with the stamp and adheredto the destination substrate. In another example, U.S. Pat. No.8,722,458 entitled Optical Systems Fabricated by Printing-Based Assemblyteaches transferring light-emitting, light-sensing, or light-collectingsemiconductor elements from a wafer substrate to a destination substrateor backplane.

In some examples of methods, in order to populate a large destinationsubstrate with components from a native source wafer, a stamp repeatedlypicks up components from different locations on a native source waferwith stamp posts and prints the components to different locations on adestination substrate. The arrangement of components on the destinationsubstrate is at least partly defined by the arrangement of thecomponents on the native source wafer and the arrangement of posts onthe stamp. The location of the stamp with respect to the native sourcewafer and the destination substrate can be controlled by anopto-electro-mechanical control system. Additional transfers to thedestination substrate can be made by picking up additional componentsfrom the native source wafer.

SUMMARY

Conventional methods of transfer printing typically involve picking up anew set of components from a source wafer for each area of destinationsubstrate to be populated with the components. The present disclosureincludes the recognition that moving a stamp, a native source wafer, ora destination substrate to provide additional components on adestination substrate increases fabrication time thereby reducingmanufacturing throughput. There is a need, therefore, for systems,structures, devices, materials, and methods that enable improvedthroughput and functionality for printed systems having variousmicro-component structures. In some embodiments, the present disclosureprovides a solution to the reduced efficiency of multiple transfersbetween a native source wafer and a destination substrate by utilizingpatterned substrates including substrate posts for selective printing ofcomponents.

The present disclosure provides, inter alia, structures, materials, andmethods for providing components on posts of a destination substrate. Inaccordance with certain embodiments, a method of printing (e.g.,micro-transfer printing) comprises providing a component source wafercomprising components, a transfer device, and a patterned substrate,wherein the patterned substrate comprises substrate posts that extendfrom a surface of the patterned substrate, picking up the componentsfrom the component source wafer by adhering the components to the stamp,and printing one or more of the picked-up components to the patternedsubstrate by disposing each of the one or more picked-up components ontoone of the substrate posts, thereby providing one or more printedcomponents in a printed structure (e.g., a micro-transfer printedstructure). In some embodiments, the transfer device is a stamp, forexample comprising a viscoelastic material such as PDMS, or anelectro-static transfer device. The components can be adhered to thesubstrate posts, for example with van der Waals forces or with anadhesive layer.

According to some embodiments, each of the one or more of the picked-upcomponents is a first picked-up component and one or more of thepicked-up components other than the one or more first picked-upcomponents is a second picked-up component and the method comprisesmoving the transfer device relative to the patterned substrate andprinting to the patterned substrate by disposing each of the one or moresecond picked-up components onto one of the substrate posts.

In some embodiments, the method comprises moving the transfer devicerelative to the patterned substrate after printing the first picked-upcomponents and printing the second picked-up components to the patternedsubstrate without picking up any components additional to the first andsecond picked-up components.

In some embodiments, each of the picked-up components comprises a broken(e.g., fractured) component tether.

In some embodiments, the transfer device picks up every component on thecomponent source wafer. In some embodiments, the transfer device picksup a subset of the components on the component source wafer. In someembodiments, the transfer device picks up every component on thecomponent source wafer within a simple closed curve on the componentsource wafer. The subset of picked-up components can be a regularrectangular array of components. All of the picked-up components can beprinted.

In some embodiments, a subset of the picked-up components is printed andno picked-up components that are not in the subset of picked-upcomponents are between the picked-up components that are in the subsetof the picked-up components. In some embodiments, a subset of thepicked-up components is printed and picked-up components that are not inthe subset of picked-up components are between the picked-up componentsthat are in the subset of the picked-up components.

The substrate posts can be disposed in a regular rectangular array andcan be enclosed in a simple closed curve, for example a rectangle.

According to some embodiments, the picked-up components are separated bya component separation distance in each of one or two dimensions and thesubstrate posts are separated by a substrate post distance in each ofone or two dimensions. The substrate post separation distance can begreater than the component separation distance.

In some embodiments, for at least one of the one or more printedcomponents, the one printed component does not extend over an edge ofthe one of the substrate posts. In some embodiments, for at least one ofthe one or more printed components, the one printed component extendsover an edge, multiple edges, opposing edges, or all of the edges of theone of the substrate posts.

Each of the one or more components can be adhered to the one of thesubstrate posts. In some embodiments, for at least one of the substrateposts, the one substrate post forms a ridge that extends in onedirection beyond one of the one or more printed components printed onthe substrate post. More than one of the one or more printed componentscan be printed on a single ridge. Similarly, a printed component can beprinted on more than one ridge or substrate post. For each of the one ormore printed components, the one of the substrate posts can be disposedbetween a center of the printed component and the substrate. In someembodiments, the one of the substrate posts on which a component isplaced is not disposed between a center of the printed component and thesubstrate.

According to some embodiments, the transfer device is a stamp comprisinga stamp post, one of the picked-up components is disposed on the stampafter being picked up, and the stamp post has a dimension substantiallythe same as a corresponding dimension of at least one of the substrateposts.

In some embodiments, a method comprises disposing a solder between eachof the one or more printed components and the one of the substrate postsand heating the solder to electrically connect a substrate postelectrode on the substrate post to a component electrode on thecomponent. Methods can comprise (i) wire bonding a wire to a componentelectrode on each of the one or more printed components, (ii) wirebonding a wire to a substrate post electrode on the one of the substrateposts, or (iii) both (i) and (ii).

According to some embodiments, a method comprises printing (e.g.,micro-transfer printing) the one or more picked-up components on to onesof the substrate posts having locations relatively different fromlocations of the one or more picked-up components on the componentsource wafer. The printed structure can be a printable module (e.g., amicro-transfer printable module) comprising at least a portion of amodule tether connected to the patterned substrate.

According to some embodiments, a device structure (e.g., amicro-transfer printed structure) comprises a patterned substratecomprising a substrate surface and a substrate post protruding from thesubstrate surface, the substrate post comprising a substrate postmaterial. A component has a component top side and a component bottomside opposite the component top side, the component bottom side disposedon the substrate post and extending over at least one edge of thesubstrate post, the component comprising a component material differentfrom the substrate post material, and the component comprising a broken(e.g., fractured) or separated component tether.

In some embodiments, the component is a first component and the printedstructure comprises a second component adhered to the substrate post.

In some embodiments, the substrate post is a ridge with a length greaterthan a width over the substrate and the substrate post has a substratepost top side to which the component bottom side is adhered. In someembodiments, a device structure comprises one or more substrate postelectrodes on the substrate post top side and the one or more substratepost electrodes is electrically connected to the component. Thesubstrate post can be electrically conductive and can be electricallyconnected to the component.

In some embodiments, a device structure comprises one or more componenttop electrodes disposed on the component top side. In some embodiments,a device structure comprises (i) a wire bond electrically connected toat least one of the one or more component top electrodes, (ii) asubstrate post electrode disposed on the substrate post and comprising awire bond electrically connected to the substrate post electrode, or(iii) both (i) and (ii). The substrate post can be electricallyconductive or can comprise one or more substrate post electrodes thatare each electrically connected to at least one of the one or morecomponent top electrodes.

In some embodiments, a device structure comprises one or more componentbottom electrodes disposed on the component bottom side. The substratepost can be electrically conductive or can comprise one or moresubstrate post electrodes that are each electrically connected to atleast one of the one or more component bottom electrodes.

In some embodiments, the component has at least one of a length and awidth less than or equal to 200 microns, less than or equal to 100microns, less than or equal to 50 microns, less than or equal to 20microns, less than or equal to 10 microns, or less than or equal to 5microns. The substrate post can be electrically conductive or comprisesone or more substrate post electrodes. The component material can be asemiconductor, the substrate post material can be a dielectric, or thesubstrate post material can be an electrical conductor.

In some embodiments, the component extends over at least two, three, orfour sides of the substrate post. The component can extend over opposingsides of the substrate post. The component can be rectangular, can beplus sign shaped, or can be disc shaped.

The component can be adhered or attached to the patterned substrate onlyby the component bottom side. The component can be an electronic or anopto-electronic component and can comprise an electronic circuit. Thecomponent can be responsive to at least one of electrical energy,optical energy, electromagnetic energy, and mechanical energy. Thecomponent can comprise electrically conductive connection posts (e.g.,component contact pads).

In some embodiments, the patterned substrate is a semiconductorsubstrate comprising an electronic circuit.

In some embodiments, the device structure is a printable module (e.g., amicro-transfer printable module) and comprises at least a portion of amodule tether connected to the patterned substrate.

In some embodiments, a module structure comprises a patterned substratehaving a substrate surface and a substrate post protruding from thesubstrate surface. A component is disposed on the substrate post. Thecomponent has a component top side and a component bottom side oppositethe component top side. The component bottom side is disposed on thesubstrate post. The component extends over at least one edge of thesubstrate post and one or more component electrodes are disposed on thecomponent. The one or more component electrodes can comprise (i) acomponent top electrode disposed on the component top side, (ii) acomponent bottom electrode disposed on the component bottom side, or(iii) both (i) and (ii).

The module structure can comprise a cavity formed or disposed in or onthe patterned substrate. The cavity can have a cavity floor and one ormore cavity walls and can contain, enclose, or surround one or morecomponents. The substrate post can be disposed on the cavity floor. Oneor more cavity walls can be formed on the patterned substrate. In someembodiments, a cap is disposed over the cavity. The cavity walls can beformed on the patterned substrate and adhered to the cap with adhesive.The cavity walls can be formed on or as part of the cap and adhered tothe patterned substrate with adhesive. Thus, in some embodiments, a capcomprises cavity walls, the cap is adhered to the cavity floor withadhesive, and the cap defines a cavity around, enclosing, or surroundingthe component. The cap can comprise a broken (e.g., fractured) orseparated cap tether.

In some embodiments, the module structure comprises two or moresubstrate posts disposed within the cavity. Two or more components canbe disposed within the cavity. The one or more component electrodes ofeach of the two or more components disposed within the cavity can beelectrically connected.

In some embodiments, a module structure can comprise two or moresubstrate posts disposed within the cavity and can comprise two or morecomponents disposed within the cavity.

In some embodiments, the one or more component electrodes of each of thetwo or more components disposed within the cavity are electricallyconnected.

In some embodiments of the module structure, the component comprises abroken (e.g., fractured) or separated component tether. The componentcan be adhered or attached to the substrate or substrate post only onthe component bottom side. The component can be adhered to the substratepost with adhesive. The component can comprise a piezo-electricmaterial. The substrate can comprise a semiconductor substratecomprising a component electronic or electrical circuit. The componentcan comprise a component material different from a substrate postmaterial.

According to some embodiments, module source wafer comprising apatterned sacrificial layer comprising one or more sacrificial portionseach adjacent to one or more anchors, wherein the one or moresacrificial portions are differentially etchable from the module sourcewafer and the patterned substrate is disposed at least partially on orover one of the one or more sacrificial portions. The sacrificialportions can comprise a material different from a module source wafermaterial. The sacrificial portions can comprise an anisotropicallyetchable material.

According to some embodiments, a module structure comprises a modulesource wafer comprising a patterned sacrificial layer comprising ananchor. The patterned substrate can be connected to the anchor by atether and disposed such that a gap exists between the patternedsubstrate and a surface of the module source wafer. The module structurecan comprise a broken (e.g., fractured) or separated module tetherconnected to the patterned substrate. The component can compriseelectrically conductive connection posts (e.g., component contact pads).

According to some embodiments, a method of making a micro-modulestructure comprises providing a substrate. The substrate has a substratesurface and the substrate comprises a substrate post protruding from thesubstrate surface. A component is disposed on the substrate post, thecomponent having a component top side and a component bottom sideopposite the component top side. The component bottom side is disposedon the substrate post and the component extends over at least one edgeof the substrate post. The method further comprises providing one ormore component electrodes disposed on the component. The one or morecomponent electrodes can comprise (i) a component top electrode disposedon the component top side, (ii) a component bottom electrode disposed onthe component bottom side, or (iii) both (i) and (ii).

In some embodiments, the substrate is patterned to form a patternedsubstrate and to form the substrate post. The component can be printed(e.g., micro-transfer printed) from a component source wafer to thesubstrate post. The component can be formed on the substrate.

In some embodiments, methods can comprise providing a cavity in or onthe substrate, the cavity having a cavity floor and one or more cavitywalls. The substrate can be etched to form the one or more cavity wallsand the cavity floor. The substrate post can be formed on the cavityfloor.

In some embodiments, methods can comprise disposing a cap over thecavity, laminating the cap over the cavity, or printing (e.g.,micro-transfer printing) the cap to dispose the cap over the cavity.

In some embodiments, methods can comprise etching the substrate to forma cavity with one or more side walls and a substrate post layer,depositing component material over the substrate, patterning thecomponent material to form the component, and etching the substrate postlayer to form the substrate post. In some embodiments, methods cancomprise providing a cap with one or more walls and printing (e.g.,micro-transfer printing) the cap with walls over the component andsubstrate post, thereby defining a cavity having one or more cavitywalls. The one or more component electrodes can be formed on thecomponent.

In some embodiments, methods can comprise providing a module sourcewafer comprising a patterned sacrificial layer comprising one or moresacrificial portions each adjacent to one or more anchors, wherein theone or more sacrificial portions are differentially etchable from thewafer and the substrate is disposed at least partially on one of the oneor more sacrificial portions. The sacrificial portions can beanisotropically etchable.

In some embodiments, methods can comprise etching one of the one or moresacrificial portions, picking up the module structure with a pick-uptransfer device, transferring the module structure to a printingtransfer device, and printing the module structure to a cap with theprinting transfer device.

One of the one or more sacrificial portions can be etched, and thesubstrate transferred to a destination substrate. The pick-up transferdevice and the printing transfer device can each be a stamp, for examplean electro-static or viscoelastic stamp.

In some embodiments, providing the component comprises providing acomponent source substrate, disposing the component over or on thecomponent source substrate, providing a sacrificial layer over at leasta portion of the component, adhering the sacrificial layer to a carriersubstrate with an adhesive, and removing the component source substrateand exposing at least a portion of the sacrificial layer. Providing thesacrificial layer can comprise forming the sacrificial layer.Embodiments can comprise forming at least one of the one or morecomponent electrodes on the component before forming the sacrificiallayer, forming a component electrode on the component after removing thecomponent source substrate, etching the sacrificial layer to form acomponent tether attaching the component to an anchor portion of theadhesive, or printing (e.g., micro-transfer printing) the component.

In some embodiments, the component comprises a piezo-electric material.

In some embodiments of the present disclosure, a device structurecomprises an acoustic wave transducer comprising a component comprisinga piezo-electric material, component electrodes disposed on thecomponent, and connection posts extending away from the component, eachof the connection posts electrically connected to one of the componentelectrodes. The component has a center and a length greater than a widthand, for each of the connection posts, a distance between the connectionpost and the center is no more than one quarter of the length (e.g., isless than one quarter of the length, is no more than one eighth of thelength, is no more than one tenth of the length, is no more than onetwentieth of the length). The component posts can be at the center ofthe component in one dimension, for example a length dimension (e.g.,that is greater than a width dimension). In some embodiments, each ofthe connection posts is closer to the component center than an end ofthe component.

In some embodiments, the component has a component top side and acomponent bottom side opposite the component top side and at least oneof the component electrodes is a component top electrode disposed on thecomponent top side. In some embodiments, the component has a componenttop side and a component bottom side opposite the component top side andat least one of the component electrodes is a component bottom electrodedisposed on the component bottom side.

In some embodiments, the acoustic wave transducer is a surface acousticwave transducer or filter, or the component is a bulk acoustic wavetransducer or filter.

In some embodiments, a device structure comprises a dielectric layerdisposed at least partially between the component and a distal end of aconnection post. The connection posts can have a distal end and aproximal end, the distal end having an area smaller than an area of theproximal end, wherein the distal end forms a sharp point. The connectionposts can comprise planar edges or a pyramidal structure.

In some embodiments, a device structure comprises a component sourcewafer comprising a sacrificial layer comprising sacrificial portions,wherein each sacrificial portion is adjacent to one or more anchors. Thecomponent can be disposed entirely, completely, or exclusively over oneof the sacrificial portions. In some embodiments, the components cancomprise portions that extend over or form part of a tether or anchor.

In some embodiments, a device structure comprises a dielectric layerdisposed between the one of the sacrificial portions and the component,wherein each of the connection posts is electrically connected to one ofthe component electrodes through the dielectric layer. One of thesacrificial portions can be differentially etchable from the anchors orcan comprise different materials, for example differentially etchablematerials. In some embodiments, one of the sacrificial portionscomprises an anisotropically etchable material. The connection posts canextend into the one of the sacrificial portions.

In some embodiments, a device structure comprises a component sourcewafer comprising a patterned sacrificial layer comprising an anchor,wherein the component is connected to the anchor by a tether anddisposed such that a gap exists between the component and a surface ofthe module source wafer.

In some embodiments, a device structure comprises a substrate having asubstrate surface and electrodes disposed on the substrate surface, andthe component disposed on the substrate surface. Each of the connectionposts can be in electrical contact with one of the electrodes.

In some embodiments, a device structure comprises a patterned layer ofadhesive adhering the connection posts to the substrate surface. Thepatterned layer of adhesive can contact only a portion of a bottomsurface of the component to the substrate surface. The component canhave at least one of a length and width less than or equal to 200microns. The patterned substrate can comprise a semiconductor comprisingan electronic substrate circuit.

In some embodiments, a device structure comprises three or at least fourconnection posts. The component can comprise at least a portion of acomponent tether.

According to some embodiments of the present disclosure, a printedstructure comprises a patterned substrate comprising a substrate surfaceand a substrate post protruding from the substrate surface. Thesubstrate post comprises a substrate post material that is an adhesive,for example a hard-cured adhesive, a partially cured or soft-curedadhesive, or a liquid adhesive. A component has a component top side anda component bottom side opposite the component top side. The componentbottom side is disposed on the substrate post and extends over at leastone edge of the substrate post.

The adhesive can be a cured adhesive, an uncured adhesive, a partiallycured adhesive, or a soft-cured adhesive. The adhesive can be a curableadhesive that is only partially cured. The adhesive can comprise anorganic material, a polymer, a resin, or an epoxy. The adhesive can be aphotoresist. The photoresist can be a positive photoresist or a negativephotoresist.

According to some embodiments, the patterned substrate comprises aplurality of substrate posts disposed in an adhesive layer forming thepattern of the patterned substrate.

According to some embodiments, the printed structure comprises one ormore connection posts extending from the component toward the patternedsubstrate. Substrate electrodes can be disposed on the patternedsubstrate adjacent to the substrate post and each of the connectionposts can be in electrical contact with one of the substrate electrodes.According to some embodiments, the adhesive is disposed between thecomponent and the substrate. According to some embodiments, the adhesiveis disposed only between the connection posts and is not in contact withthe connection posts so that none of the adhesive is disposed on theconnection posts. According to some embodiments, the adhesive isdisposed only between the substrate electrodes and is not in contactwith the substrate electrodes so that none of the adhesive is disposedon the substrate electrodes. According to some embodiments, adhesive isdisposed on only a portion of the substrate electrodes but not on theone or more connection posts. According to some embodiments, adhesive isdisposed on only a portion of the one or more connection posts but noton the substrate electrodes,

According to some embodiments of the present disclosure, the connectionposts extend into or penetrate (e.g., pierce) the electrical substrateelectrodes to make an electrical contact between the component and thesubstrate electrodes. A height of the connection posts can be greaterthan or equal to the height of the substrate post. According to someembodiments, (i) the components comprise connection posts extendingtowards the patterned substrate, (ii) the patterned substrate comprisessubstrate electrodes disposed between the substrate posts, and (iii) thesubstrate posts each have a height greater than or equal to a height ofconnection posts when uncured or soft-cured and subsequently a smallerheight that is less than or equal to a height of connection posts afterhard curing when the connection posts are in electrical contact with thesubstrate electrodes.

According to some embodiments, the substrate electrodes aresubstantially planar and the connection posts have a substantiallyplanar distal end. According to some embodiments, the one or moreconnection posts are each a substantially planar component contact pad.

According to some embodiments, the substrate electrodes are closertogether than any portion of the connection posts. According to someembodiments, the connection posts are closer together than any portionof the substrate electrodes. According to some embodiments, the area ofa cross section of the substrate post between the component and thesubstrate is less than an area of a cross section bounded by thecomponent, the substrate, and the connection posts. According to someembodiments, the area of a cross section of the substrate post betweenthe component and the substrate is less than an area of a cross sectionbounded by the component, the substrate, and the substrate electrodes.

According to some embodiments of the present disclosure, solder isdisposed on the substrate electrodes and the solder coats at least aportion of the connection posts. According to some embodiments, anon-directional deposition of metal coats both the connection posts andthe substrate electrodes, for example by chemical vapor, electrolessplating, or electroplating. According to some embodiments, theconnection posts are wave soldered. Heating and then cooling the soldercan physically connect each of the connection posts to one of thesubstrate electrodes.

According to some embodiments of the present disclosure, the adhesiveholds the component in compression against the substrate.

According to some embodiments of the present disclosure, the componentcomprises a fractured, broken, or separated tether, for example as aconsequence of micro-transfer printing the component from a componentsource wafer to the substrate post.

According to some embodiments of the present disclosure, a method ofmaking a printed structure comprises providing a component source wafercomprising components and a transfer device, providing a substrate,disposing a layer of adhesive on the substrate (e.g., a curable liquidlayer of adhesive), and patterning the layer of adhesive to formsubstrate posts that extend from a surface of the patterned substrate,picking up the components from the component source wafer by adheringthe components to the transfer device, and printing one or more of thepicked-up components to the patterned substrate by disposing each of theone or more picked-up components onto one of the substrate posts,thereby providing one or more printed components in a printed structure.According to some embodiments, the adhesive layer is a negativephotoresist and methods comprise exposing the layer of adhesive throughthe patterned substrate to pattern the layer of adhesive. The layer ofadhesive can be hard-cured and the patterned substrate can be wavesoldered after the hard cure to form or improve an electrical connectionbetween the connection posts and the substrate electrodes. Substrateelectrodes can be substrate contact pads. According to some embodiments,electrical connection between the connection posts and the substrateelectrodes are enhanced by a non-directional metal deposition such as bychemical vapor, electroless plating, or electroplating.

Some embodiments of the present disclosure comprise soft curing theadhesive layer, patterning the adhesive layer to form substrate posts,printing each picked-up component of the one or more of the picked-upcomponents onto the substrate posts, and hard curing the patternedadhesive layer. Connection posts can extend from the component, thesubstrate can comprise substrate electrodes coated with solder, andmethods of the present disclosure can comprise heating and cooling thesolder to electrically connect each substrate electrode to one of theconnection posts. Heating and cooling the solder can cure the adhesivein a common step.

According to some embodiments, providing the patterned substratecomprises providing a substrate and printing the substrate posts ontothe substrate in a pattern thereby forming the patterned substrate, forexample by inkjet printing.

According to some embodiments, the adhesive is curable and the methodsof the present disclosure comprise curing (e.g., hard curing) thesubstrate posts after the printing. Substrate posts can have a smallerheight after curing.

According to some embodiments, a printed structure comprises a patternedsubstrate comprising a substrate surface and a substrate post protrudingfrom the substrate surface, the substrate post comprising a substratepost material that is an adhesive, a component having a component topside and a component bottom side opposite the component top side, thecomponent bottom side disposed on the substrate post and extending overat least one edge of the substrate post, and one or more connectionposts (e.g., contact pads) disposed on the bottom side. According tosome embodiments, substrate electrodes are disposed on the patternedsubstrate adjacent to the substrate post and each of the one or morecontact pads is in electrical contact with one of the substrateelectrodes.

BRIEF DESCRIPTION OF THE DRAWINGS

The foregoing and other objects, aspects, features, and advantages ofthe present disclosure will become more apparent and better understoodby referring to the following description taken in conjunction with theaccompanying drawings, in which:

FIGS. 1A-12 are successive illustrations of structures formed during amethod according to illustrative embodiments of the present disclosure;

FIG. 1A is a perspective and FIG. 1B is a cross section taken alongcross section line A of FIG. 1A of a stamp and component source waferaccording to illustrative embodiments of the present disclosure;

FIG. 2 is a cross section of a stamp in contact with components on acomponent source wafer according to illustrative embodiments of thepresent disclosure;

FIG. 3A is a perspective and FIG. 3B is a cross section taken alongcross section line A of FIG. 3A of a stamp with components removed froma component source wafer according to illustrative embodiments of thepresent disclosure;

FIG. 4A is a perspective and FIG. 4B is a cross section taken alongcross section line A of FIG. 4A of a stamp and patterned substratebefore micro-transfer printing from the stamp to the patterned substrateaccording to illustrative embodiments of the present disclosure;

FIG. 5 is a cross section of a stamp micro-transfer printing a firstsubset of components to a patterned substrate according to illustrativeembodiments of the present disclosure;

FIG. 6A is a perspective and FIG. 6B is a cross section taken alongcross section line A of FIG. 6A of a stamp and patterned substratebefore micro-transfer printing a second subset of components from thestamp to the patterned substrate according to illustrative embodimentsof the present disclosure;

FIG. 7 is a cross section of a stamp micro-transfer printing a secondsubset of components to a patterned substrate according to illustrativeembodiments of the present disclosure;

FIG. 8A is a perspective and FIG. 8B is a cross section taken alongcross section line A of FIG. 8A of a stamp and patterned substrate aftermicro-transfer printing a second subset of components from the stamp tothe patterned substrate according to illustrative embodiments of thepresent disclosure;

FIGS. 9-12 are successive perspectives of structures following FIGS. 8Aand 8B of a stamp and patterned substrate before and aftermicro-transfer printing successive subsets of components from the stampto the patterned substrate according to illustrative embodiments of thepresent disclosure;

FIG. 13 is a flow diagram of a micro-transfer printing and constructionprocess corresponding to FIGS. 1A to 12 according to illustrativemethods of the present disclosure;

FIG. 14 is a flow diagram illustrating a construction method;

FIGS. 15-16 are perspectives of a stamp populated with components beforemicro-transfer printing the components to a patterned substrateaccording to illustrative embodiments of the present disclosure;

FIG. 17A is a perspective and FIG. 17B is a corresponding cross sectiontaken along cross section line A of FIG. 17A of a componentmicro-transfer printed to a patterned substrate where the component doesnot extend over an edge of a substrate post according to illustrativeembodiments of the present disclosure;

FIG. 18A is a perspective and FIG. 18B is a corresponding cross sectiontaken along cross section line A of FIG. 18A of a componentmicro-transfer printed to a patterned substrate where the componentextends over the edges of a substrate post according to illustrativeembodiments of the present disclosure;

FIG. 19A is a perspective and FIGS. 19B and 19C are correspondingmicrographs of a component micro-transfer printed to a patternedsubstrate where the component extends over the edges of a substrate postin one direction but not in an orthogonal direction according toillustrative embodiments of the present disclosure;

FIG. 20A is a perspective and FIG. 20B is a corresponding cross sectiontaken along cross section line A of FIG. 20A of a stamp micro-transferprinting a component to a patterned substrate where a stamp post has anarea substantially equal to an area of a substrate post to which thecomponent is micro-transfer printed according to illustrativeembodiments of the present disclosure;

FIG. 21 is a perspective of two components micro-transfer printed to acommon substrate post according to illustrative embodiments of thepresent disclosure;

FIG. 22A is a perspective and FIG. 22B is a corresponding cross sectiontaken along cross section line A of FIG. 22A of a component, substratepost, substrate circuit, and patterned substrate electrodes according toillustrative embodiments of the present disclosure;

FIGS. 22C-22D are cross sections of a component, substrate post,substrate circuit, and patterned substrate wire bonds according toillustrative embodiments of the present disclosure;

FIG. 23A is a perspective and FIG. 23B is a corresponding cross sectiontaken along cross section line A of FIG. 23A of extensive componentelectrodes with a substrate post, substrate circuit, and patternedsubstrate electrodes according to illustrative embodiments of thepresent disclosure;

FIGS. 23C-23E are perspectives of extensive component electrodes with asubstrate post and patterned substrate electrodes according toillustrative embodiments of the present disclosure;

FIGS. 24A-24C are perspectives of components having different shapesaccording to illustrative embodiments of the present disclosure;

FIGS. 25A, 25B and 26 are perspectives of a component, substratepost(s), and electrodes according to illustrative embodiments of thepresent disclosure;

FIGS. 27-30 are cross sections of a component within a cavity accordingto illustrative embodiments of the present disclosure;

FIGS. 31-35 are flow diagrams of construction methods according toillustrative embodiments of the present disclosure;

FIGS. 36A-36L are successive cross sections of structures formed duringa method according to illustrative embodiments of the presentdisclosure;

FIGS. 37A-37C are successive cross sections of structures formed duringa method according to illustrative embodiments of the presentdisclosure;

FIG. 38 is a cross section of a micro-transfer printable moduleaccording to illustrative embodiments of the present disclosure;

FIGS. 39A-39H are successive cross sections of structures formed duringa method according to illustrative embodiments of the presentdisclosure;

FIG. 40 is a perspective of a component comprising two connection postslocated near a center of the component according to illustrativeembodiments of the present disclosure;

FIG. 41 is a perspective of a component comprising four connection postslocated near a center of the component according to illustrativeembodiments of the present disclosure;

FIG. 42 is a top plan view of a micro-transfer printed componentcorresponding to FIG. 41 comprising four connection posts located near acenter of the component according to illustrative embodiments of thepresent disclosure;

FIG. 43 is a cross section of a component in accordance with thecomponent shown in FIG. 40 or FIG. 41 comprising two or four connectionposts located near a center of the component according to illustrativeembodiments of the present disclosure;

FIG. 44 is a perspective of a micro-transfer printable component havingtwo connection posts located near each end of the component in alength-wise direction according to illustrative embodiments of thepresent disclosure;

FIG. 45 is a cross section of a component corresponding to FIG. 44having connection posts embedded in or penetrating substrate electrodeson a patterned substrate according to illustrative embodiments of thepresent disclosure;

FIGS. 46A-46B are cross sections of micro-transfer printable componentswith connection posts on a component source wafer according toillustrative embodiments of the present disclosure;

FIG. 47 is a perspective of a micro-transfer printed component inaccordance with the component shown in FIG. 40 or FIG. 46A havingpatterned component top electrodes electrically connected to a substratecircuit on a patterned substrate according to illustrative embodimentsof the present disclosure; and

FIG. 48 is a perspective of a micro-transfer printed component inaccordance with the component shown in FIG. 44 or 46B having a patternedcomponent top electrode electrically connected to a substrate circuit ona patterned substrate according to illustrative embodiments of thepresent disclosure;

FIGS. 49A-49F are successive cross sections of structures formed duringa method of making micro-transfer printable components according toillustrative embodiments of the present disclosure;

FIGS. 50A and 50B are cross sections of a micro-transfer printedcomponent on a substrate post according to illustrative embodiments ofthe present disclosure;

FIG. 51 is a flow diagram illustrating methods according to illustrativeembodiments of the present disclosure;

FIGS. 52A-52I are successive cross sections of structures formed duringa method of making micro-transfer printable components according toillustrative embodiments of the present disclosure; and

FIGS. 53A-53F are successive cross sections of structures formed duringa method of making micro-transfer printable components according toillustrative embodiments of the present disclosure; and

FIGS. 54A-54C are cross sections of a micro-transfer printed componenton a substrate post according to illustrative embodiments of the presentdisclosure.

The perspectives shown in FIGS. 1A, 3A, 4A, 6A, 8A, 9-12, 19, 20, 25Aand 25B are exploded illustrations with exaggerated viewing angles. Thetwo cross section lines A indicated in some of the perspective Figuresare actually congruent and illustrate the same cross section line fordifferent elements of the figure.

The features and advantages of the present disclosure will become moreapparent from the detailed description set forth below when taken inconjunction with the drawings, in which like reference charactersidentify corresponding elements throughout. In the drawings, likereference numbers generally indicate identical, functionally similar,and/or structurally similar elements. The figures are not necessarilydrawn to scale.

DETAILED DESCRIPTION OF CERTAIN EMBODIMENTS

Certain embodiments of the present disclosure are directed towardmethods of printing (e.g., micro-transfer printing) arrays of componentsfrom a component source wafer to a patterned substrate using a transferdevice (e.g., stamp), where the patterned substrate comprises structuresthat extend from a surface of the patterned substrate. Each suchstructure is referred to herein as a substrate post and the substratepost serves to contact and adhere a picked-up component disposed(temporarily) on the transfer device. Thus, in some embodiments, onlythose components present on a stamp that contact a substrate post areprinted (e.g., transfer printed) to the patterned substrate so that thearrangement of printed (e.g., micro-transfer printed) components on thepatterned substrate is at least partially defined by the arrangement ofsubstrate posts on the patterned substrate, and not solely by thearrangement of components on the stamp. According to some embodiments, adevice structure comprises an acoustic wave transducer comprising acomponent (e.g., and one or more component electrodes). An acoustic wavetransducer (e.g., a bulk or surface acoustic wave transducer) can be aportion of an acoustic wave filter or sensor.

Referring to the sequential cross sections and perspectives of FIGS.1A-12 and the flow diagram of FIG. 13, according to some embodiments, amethod of micro-transfer printing comprises providing a component sourcewafer 40 comprising components 30 in step 100 and providing a transferdevice 20 (e.g., a stamp 20) in step 110 (as shown in the exploded FIG.1A perspective and corresponding cross section FIG. 1B taken along crosssection line A of FIG. 1A). Stamp 20 can, but does not necessarily,comprise stamp posts 22, each with a stamp post area 26, that protrudefrom stamp 20 to contact components 30 when stamp 20 is pressed againstcomponents 30. As shown in FIG. 1B, components 30 are entirely disposedover, and can be formed on, sacrificial portions 82 spatially separatedby anchors 50 in sacrificial layer 81 of component source wafer 40.Components 30 can be, but are not necessarily, arranged in a rectangulararray of components 30, for example in a regular two-dimensionalarrangement within a rectangular simple closed curve 46. A dielectriclayer 44 disposed over patterned substrate 10 and sacrificial portions82 connects each component 30 with a component tether 52 to an anchor50. Component tethers 52 can be laterally connected to anchors 50 (asshown) or disposed in other locations, for example beneath components 30(shown in FIGS. 39D-39H discussed below).

Reference is made throughout the present description to examples ofmicro-transfer printing with stamp 20 when describing certain examplesof printing components 30 (e.g., in describing FIGS. 1A-12). Similarother embodiments are expressly contemplated where a transfer device 20that is not a stamp 20 is used to similarly print components 30. Forexample, in some embodiments, a transfer device 20 that is avacuum-based or electrostatic transfer device 20 can be used to printcomponents 30. A vacuum-based or electrostatic transfer device 20 cancomprise a plurality of transfer posts, each transfer post beingconstructed and arranged to pick up a single component 30 (similarly tostamp posts 22 in stamp 20).

Referring to FIG. 2, sacrificial portions 82 (shown in FIG. 1A) aresacrificed, for example by etching sacrificial portions 82 to form gaps84 (indicated by arrows), so that components 30 are suspended over gaps84 and attached to anchors 50 of component source wafer 40 by componenttethers 52 that maintain the physical position of components 30 relativeto (e.g., with respect to) component source wafer 40 after sacrificialportions 82 are etched. (Components 30 shown in FIG. 2 are said tocomprise at least a portion of a component tether 52, which may break orseparate during a pick-up portion of a printing.) Stamp 20 is moved intoposition relative to component source wafer 40, for example by anopto-mechatronic motion platform, in step 130 and components 30 arepicked up from component source wafer 40 by adhering components 30 tostamp 20, for example by pressing stamp 20 against components 30 oncomponent source wafer 40 with the motion platform and adheringcomponents 30 to the distal ends of stamp posts 22, for example with vander Waals or electrostatic forces.

Referring to the FIG. 3A perspective and FIG. 3B cross section takenalong cross section line A of FIG. 3A, stamp 20 in contact withcomponents 30 suspended over gaps 84 is then removed from componentsource wafer 40 by the motion platform, fracturing dielectric layer 44component tethers 52 from anchors 50 to form fractured component tethers53 and picking up components 30 from component source wafer 40 withstamp 20 in step 140. (Fractured component tethers 53 are said to eachbe at least a portion of a component tether 53.) For clarity, components30 adhered to stamp 20 or stamp posts 22 of stamp 20 are also referredto as stamp components 30S. Thus, picked-up stamp components 30S cancomprise a separated or broken (e.g., fractured) component tether 53.

Referring to the perspective of FIG. 4A and cross section of FIG. 4Btaken along cross section line A of FIG. 4A, a patterned substrate 10comprising substrate posts 12 that extend from a substrate surface 11 ofpatterned substrate 10 is provided in step 120. Patterned substrate 10is patterned at least because of substrate posts 12 formed on or inpatterned substrate 10. Substrate posts 12 can comprise the samematerial as patterned substrate 10 or can be a patterned structureformed by processing a substrate, for example a structured substrate.Substrate posts 12 are spatially separated over patterned substrate 10by a substrate post separation distance 14 in each of one or twodimensions. In step 150, stamp 20 and stamp components 30S withfractured component tethers 53 are moved into position relative to(e.g., with respect to) patterned substrate 10 and substrate posts 12.Stamp components 30S can be spatially separated by a stamp componentseparation distance 24 in each of one or two dimensions that isdifferent from substrate post separation distance 14, for examplesmaller, and an extent of stamp 20 (e.g., a convex hull of stamp posts22) can be different from an extent of patterned substrate 10 (e.g., aconvex hull of substrate posts 12). Hence, substrate post separationdistance 14 can be greater than component separation distance 24. Thus,in some embodiments, a subset of stamp components 30S are selected bysubstrate posts 12 to micro-transfer print the subset of stampcomponents 30S to the selecting substrate posts 12. In the example ofFIGS. 4A and 4B, every other stamp component 30S in two dimensionspositioned on the front left of stamp 20 is transfer printed tocorresponding adjacent substrate posts 12 on the front left of patternedsubstrate 10 so that components 30 micro-transfer-printed to substrateposts 12 (referred to herein as substrate post components 30P) arespatially separated by twice the substrate post separation distance 14in each of the two dimensions over patterned substrate 10 as component30S separated by stamp component separation distance 24. In someembodiments, as shown in FIG. 4A, components 30 have a component area 36that is substantially equal to a substrate post area 18 of substrateposts 12.

Referring to FIG. 5, in step 160 one or more of picked-up stampcomponents 30S with fractured component tethers 53 are printed topatterned substrate 10 by disposing each of one or more picked-up stampcomponents 30S onto a substrate post 12 protruding from substratesurface 11 of patterned substrate 10 to provide micro-transfer-printedcomponents 30 on substrate posts 12, referred to as substrate postcomponents 30P. Not all of stamp components 30S need contact a substratepost 12, so that substrate posts 12 can effectively select a subset ofstamp components 30S from stamp posts 22 of stamp 20. Stamp components30S that contact a substrate post 12 are adhered to substrate post 12and those stamp components 30S that do not contact a substrate post 12remain adhered to stamp 20, for example to a stamp post 22.

Once substrate post components 30P contacting substrate posts 12 areadhered to substrate posts 12, stamp 20 can be removed and, if all ofcomponent 30 are not yet micro-transfer printed from stamp 20 (step170), stamp 20 is repositioned with respect to patterned substrate 10(repeating step 150 and as shown in the perspective of FIG. 6A and crosssection of FIG. 6B taken along cross section line A of FIG. 6A) tomicro-transfer print a different subset of stamp components 30S withfractured component tethers 53 from stamp posts 22 to a different subsetof substrate posts 12 on substrate surface 11 of patterned substrate 10(repeating step 160 and as shown in the cross section of FIG. 7). In theexample of FIG. 6B, every other stamp component 30S in two dimensionspositioned on the front right of stamp 20 is micro-transfer printed tocorresponding adjacent substrate posts 12 on the front right ofpatterned substrate 10 so that micro-transfer printed substrate postcomponents 30P are spatially separated by twice substrate postseparation distance 14 in each of the two dimensions over patternedsubstrate 10 compared to stamp component separation distance 24. Stamp20 is removed as shown in the perspective of FIG. 8A and cross sectionof FIG. 8B taken along cross section line A of FIG. 8A, leavingsubstrate post components 30P adhered to front right substrate posts 12of patterned substrate 10.

If components 30 are not all transferred the process is not done (step170) and the same process steps 150 and 160 are repeated again to selectand transfer back left stamp components 30S with fractured componenttethers 53 on stamp posts 22 of stamp 20 to back left substrate posts 12on substrate surface 11 of patterned substrate 10 (shown in theperspective of FIG. 9 before micro-transfer printing and the perspectiveof FIG. 10, after micro-transfer printing) and then transfer back rightstamp components 30S to back right substrate posts 12 of patternedsubstrate 10 (shown in the perspective of FIG. 11 before transferprinting and the perspective of FIG. 12, after transfer printing). Whenall of components 30 are micro-transfer printed to substrate posts 12,the process is complete (step 180), as shown in FIG. 12.

Thus, methods according to certain embodiments can comprisemicro-transfer printing components 30 onto substrate posts 12 havinglocations relatively different from the locations of components 30 oncomponent source wafer 40, so that the extent of micro-transfer printedcomponents 30 over patterned substrate 10 is larger than the extent ofcomponents 30 over component source wafer 40.

In some embodiments, one or more of picked-up stamp components 30S arefirst picked-up stamp components 30S and one or more of picked-up stampcomponents 30S other than first picked-up stamp components 30S that arenot printed are second picked-up stamp components 30S so that first andsecond stamp components 30S are disjoint subsets of stamp components 30Son stamp 20. Methods according to certain embodiments can comprisemoving stamp 20 with respect to patterned substrate 10 and printing topatterned substrate 10 by disposing each first picked-up stamp component30S onto a substrate post 12 and the disposing each second picked-upstamp component 30S onto a substrate post 12 without picking up any morecomponents 30 from component source wafer 40. Stamp 20 can be movedrelative (e.g., with respect to) patterned substrate 10 by moving stamp20 with a fixed location of patterned substrate 10, by moving patternedsubstrate 10 with a fixed location of stamp 20 or moving both stamp 20and patterned substrate 10 (e.g., in opposing directions), for example.

In some embodiments, the order in which stamp components 30S are printed(e.g., front right stamp components 30S versus back left stampcomponents 30S) is arbitrary. Likewise, the order in which substrateposts 12 are selected for printing can be arbitrary. For example, thefront right stamp components 30S could be printed to back left substrateposts 12 as a first printing step in certain embodiments.

Certain embodiments provide an advantage in enabling multiple component30 print steps to a substrate without intervening pickup steps from acomponent source wafer 40 with a stamp 20. In some embodiments,elimination of intervening pickup steps improves manufacturingthroughput. Referring to FIG. 14 and in contrast to the stepsillustrated in FIG. 13, after providing a component source wafer 40 instep 100, a stamp 20 in step 110, and an unpatterned substrate in step121, stamp 20 is aligned with component source wafer 40 in step 130,stamp components 30S are picked up from component source wafer 40 instep 140, and stamp 20 is aligned with the unpatterned substrate in step151. In the absence of substrate posts 12 as on the unpatternedsubstrate, all of stamp components 30S on stamp 20 transfer to theunpatterned substrate in print step 161, because all of stamp components30S are in contact with a surface of the unpatterned substrate, and thepick-up and print processes are both repeated, necessitating a pickupstep 140 for every print step 161 until all of components 30 aremicro-transfer printed (step 170) and the process completed (step 180).In contrast, as shown in FIG. 13, some embodiments enable a singlepickup step 140 followed by multiple print steps 160, thus improvingprinting throughput. For example, FIGS. 1A-12 illustrate a single pickupstep 140 followed by four print steps 160. In some embodiments, therelative number of pickup and print steps are at least partly specifiedby the number and arrangement of stamp components 30S on stamp 20 andthe number and arrangement of substrate posts 12 on patterned substrate10.

Thus, according to some embodiments, the printed substrate postcomponents 30P of one or more picked-up stamp components 30S are firstcomponents 30 (e.g., first picked-up components) and one or more ofpicked-up stamp components 30S other than the first components 30 aresecond components 30 (e.g., second picked-up components) and methodscomprise moving stamp 20 with relative to (e.g., with respect to)patterned substrate 10 after printing first component 30 and printingsecond components 30 to patterned substrate 10 without picking up anycomponents 30 additional to first and second components 30.

According to some embodiments, micro-transfer printing can include anymethod of transferring components 30 from a source substrate (e.g.,component source wafer 40) to a destination substrate (e.g., patternedsubstrate 10) by contacting components 30 on the source substrate with apatterned or unpatterned stamp surface of a stamp 20 to removecomponents 30 from the source substrate, transferring stamp 20 andcontacted components 30 to the destination substrate, and contactingcomponents 30 to a surface of the destination substrate. Components 30can be adhered to stamp 20 or the destination substrate by, for example,van der Waals forces, electrostatic forces, magnetic forces, chemicalforces, adhesives, or any combination of the above. In some embodiments,components 30 are adhered to stamp 20 with separation-rate-dependentadhesion, for example kinetic control of viscoelastic stamp materialssuch as can be found in elastomeric transfer devices such as a PDMSstamp 20. Stamps 20 can be patterned or unpatterned and can comprisestamp posts 22 having a stamp post area 26 on the distal end of stampposts 22. Stamp posts 22 can have a length, a width, or both a lengthand a width, similar or substantially equal to a length, a width, orboth a length and a width of component 30. In some embodiments, asdiscussed further below, stamp posts 22 can be smaller than components30 or have a dimension, such as a length and/or a width, substantiallyequal to or smaller than a length or a width of substrate posts 12 inone or two orthogonal directions. In some embodiments, stamp posts 22each have a contact surface of substantially identical area.

In exemplary methods, a viscoelastic elastomer (e.g., PDMS) stamp 20(e.g., comprising a plurality of stamp posts 22) is constructed andarranged to retrieve and transfer arrays of components 30 from theirnative component source wafer 40 onto non-native patterned substrates10. In some embodiments, stamp 20 mounts onto motion-plus-opticsmachinery (e.g., an opto-mechatronic motion platform) that can preciselycontrol stamp 20 alignment and kinetics with respect to both componentsource wafers 40 and patterned substrates 10 with substrate posts 12.During micro-transfer printing, the motion platform brings stamp 20 intocontact with components 30 on component source wafer 40, with opticalalignment performed before contact. Rapid upward movement of theprint-head (or, in some embodiments, downward movement of componentsource wafer 40) breaks (e.g., fractures) or separates componenttether(s) 52 forming broken (e.g., fractured) or separated componenttethers 53, transferring component(s) 30 to stamp 20 or stamp posts 22.The populated stamp 20 then travels to patterned substrate 10 (or viceversa) and one or more components 30 are then aligned to substrate posts12 and printed.

A component source wafer 40 can be any source wafer or substrate withtransfer printable components 30 that can be transferred with a transferdevice 20 (e.g., a stamp 20). For example, a component source wafer 40can be or comprise a semiconductor (e.g., silicon) in a crystalline ornon-crystalline form, a compound semiconductor (e.g., comprising GaN orGaAs), a glass, a polymer, a sapphire, or a quartz wafer. Sacrificialportions 82 can be formed of a patterned oxide (e.g., silicon dioxide)or nitride (e.g., silicon nitride) layer or can be an anisotropicallyetchable portion of sacrificial layer 81 of component source wafer 40.Typically, component source wafers 40 are smaller than patternedsubstrates 10.

Components 30 can be any transfer printable structure, for exampleincluding any one or more of a wide variety of active or passive (oractive and passive) components 30. Components can be any one or more ofintegrated devices, integrated circuits (such as CMOS circuits),light-emitting diodes, photodiodes, sensors, electrical or electronicdevices, optical devices, opto-electronic devices, magnetic devices,magneto-optic devices, magneto-electronic devices, and piezo-electricdevice, materials or structures. Components 30 can comprise electroniccomponent circuits 34 that operate component 30. Component 30 can beresponsive to electrical energy, to optical energy, to electromagneticenergy, or to mechanical energy, for example. In some embodiments, anacoustic wave transducer 94 comprises component 30. In some embodiments,two acoustic wave transducers 94 both comprise component 30, for examplewhen used in an acoustic wave filter or sensor.

Components 30 formed or disposed in or on component source wafers 40 canbe constructed using integrated circuit, micro-electro-mechanical, orphotolithographic methods for example. Components 30 can comprise one ormore different component materials, for example non-crystalline (e.g.,amorphous), polycrystalline, or crystalline semiconductor materials suchas silicon or compound semiconductor materials or non-crystalline orcrystalline piezo-electric materials. In some embodiments, component 30comprises a layer of piezo-electric material disposed over or on a layerof dielectric material, for example an oxide or nitride such as silicondioxide or silicon nitride.

In certain embodiments, components 30 can be native to and formed onsacrificial portions 82 of component source wafers 40 and can includeseed layers for constructing crystalline layers on or in componentsource wafers 40. Components 30, sacrificial portions 82, anchors 50,and component tethers 52 can be constructed, for example usingphotolithographic processes. Components 30 can be micro-devices havingat least one of a length and a width less than or equal to 200 microns,less than or equal to 100 microns, less than or equal to 50 microns,less than or equal to 25 microns, less than or equal to 15 microns, lessthan or equal to 10 microns, or less than or equal to five microns, andalternatively or additionally a thickness of less than or equal to 50microns, less than or equal to 25 microns, less than or equal to 15microns, less than or equal to 10 microns, less than or equal to fivemicrons, less than or equal to two microns, or less than or equal to onemicron. Components 30 can be unpackaged dice (each an unpackaged die)transferred directly from native component source wafers 40 on or inwhich components 30 are constructed to patterned substrate 10.

Anchors 50 and component tethers 52 can each be or can comprise portionsof component source wafer 40 that are not sacrificial portions 82 andcan include layers formed on component source wafers 40, for exampledielectric or metal layers and for example layers formed as a part ofphotolithographic processes used to construct or encapsulate components30.

Patterned substrate 10 can be any destination substrate or targetsubstrate with substrate posts 12 to which components 30 are transferred(e.g., micro-transfer printed), for example flat-panel displaysubstrates, printed circuit boards, or similar substrates can be used invarious embodiments. Patterned substrates 10 can be, for examplesubstrates comprising one or more of glass, polymer, quartz, ceramics,metal, and sapphire. Patterned substrates 10 can be semiconductorsubstrates (for example silicon) or compound semiconductor substrates.

In some embodiments, a layer of adhesive 16, such as a layer of resin,polymer, or epoxy, either curable or non-curable, adheres components 30onto substrate posts 12 of patterned substrate 10 and can be disposed,for example by coating or lamination (e.g., as shown in FIGS. 17A and17B discussed below). In some embodiments, a layer of adhesive 16 isdisposed in a pattern, for example between electrical substrate postelectrodes 64 on a substrate post 12 or component electrodes 61 on acomponent 30. In some embodiments, a layer of adhesive 12 is disposed ina pattern, for example over substrate post electrodes 64 to improvecontact between connection posts 67 extending from a component 30 andsubstrate posts electrodes 64. A layer of adhesive can be disposed usinginkjet, screening, or photolithographic techniques, for example. In someembodiments, a layer of adhesive 16 is coated, for example with a sprayor slot coater, and then patterned, for example using photolithographictechniques. A patterned layer of adhesive can provide substrate posts12, for example by coating and imprinting or photolithographicprocessing or by inkjet deposition. In some embodiments, solder 68(e.g., as shown in FIGS. 22C and 22D and discussed below) ispattern-wise coated and disposed on substrate post 12 or componentelectrodes 61, for example by screen printing, and improves anelectrical connection between a component 30 and an electrical conductoron a substrate post 12.

In some embodiments, a substrate post 12 is any protuberance orprotrusion extending from a substrate surface 11 of patterned substrate10. In some embodiments, substrate posts 12 have a substantiallyrectangular cross section. In some embodiments, substrate posts 12 havenon-rectangular cross sections, such as circular or polygonal crosssections for example. In some embodiments, substrate posts 12 have aflat surface on a distal end of each substrate post 12 in a directionparallel to the patterned substrate 10 surface, e.g., can be a mesa. Insome embodiments, substrate posts 12 can comprise any material to whichcomponents 30 can be adhered. A substrate post 12 can be a pedestal orpost and can comprise the same material as patterned substrate 10 or cancomprise a different material from patterned substrate 10 or component30. For example, in some embodiments, substrate posts 12 comprise thesame material (e.g., silicon or other semiconductor materials) aspatterned substrate 10 and are patterned in substrate 10, for example bypatterned etching using photoresists and other photolithographicprocesses, stamping, or molding. In some embodiments, substrate posts 12are formed on patterned substrate 10 (e.g., by coating). In someembodiments, substrate posts 12 comprise different materials fromsubstrate 10, for example by coating a material in a layer on substrate10 and pattern-wise etching the coated layer to form substrate posts 12.

For example, a substrate post 12 can be or comprise a dielectricmaterial, such as an oxide (e.g., silicon dioxide) or nitride (e.g.,silicon nitride) or polymer, resin, or epoxy and can be organic orinorganic. Substrate posts 12 can be a cured resin and can be depositedin an uncured state and cured or patterned before components 30 aremicro-transfer printed to substrate posts 12 or cured after components30 are micro-transfer printed to substrate posts 12. Substrate posts 12can be electrically conductive and comprise, for example, metals ormetallic materials or particles. Substrate posts 12 can be formed usingphotolithographic processes, for example substrate posts 12 can beformed by coating a resin over a substrate and then patterning andcuring the resin using photolithographic processes (e.g., coating aphotoresist, exposing the photoresist to patterned radiation, curing thephotoresist, etching the pattern to form substrate posts 12 andpatterned substrate 10, and stripping the photoresist). Substrate posts12 can be constructed by inkjet deposition or imprinting methods, forexample using a mold, and can be imprinted structures.

Patterned electrical conductors (e.g., wires, traces, or electrodes(e.g., electrical contact pads) such as those found on printed circuitboards, flat-panel display substrates, and in thin-film circuits) can beformed on any combination of components 30, substrate posts 12, andpatterned substrate 10, and any one can comprise electrodes (e.g.,electrical contact pads) that electrically connect to components 30, forexample as described further below with respect to FIGS. 21-23. Suchpatterned electrical conductors and electrodes (e.g., contact pads) cancomprise, for example, metal, transparent conductive oxides, or curedconductive inks and can be constructed using photolithographic methodsand materials, for example metals such as aluminum, gold, or silverdeposited by evaporation and patterned using pattern-wise exposed,cured, and etched photoresists, or constructed using imprinting methodsand materials or inkjet printers and materials, for example comprisingcured conductive inks deposited on a surface or provided inmicro-channels in or on patterned substrate 10 or substrate posts 12, orboth.

According to some embodiments, stamp 20 can pick up every component 30on component source wafer 40, as shown in FIG. 3A. In some embodiments,stamp 20 picks up a subset of components 30 on component source wafer40. In some embodiments, stamp 20 picks up every component 30 oncomponent source wafer 40 within a simple closed curve 46 (shown in FIG.1A) on component source wafer 40, for example every component 30 withina rectangle on component source wafer 40. In some embodiments, stamp 20picks up a subset of components 30 on component source wafer 40 within asimple closed curve 46, for example every other component 30 within arectangle on component source wafer 40. Thus, in some embodiments, thesubset of picked-up stamp components 30S forms a regular rectangulararray, for example matching an array or sub-array of components 30 oncomponent source wafer 40 or a subset of such components 30.

In some embodiments, referring to FIGS. 15 and 16, all of picked-upstamp components 30S are micro-transfer printed so that, after a singlemicro-transfer printing, no stamp components 30S are adhered to stamp20, for example to stamp posts 22. As shown in FIG. 15, a stampcomponent 30S is transfer printed to each of substrate posts 12 onpatterned substrate 10 and all of stamp components 30S on stamp posts 22of stamp 20 are micro-transfer printed. As shown in FIG. 16, only asubset of substrate posts 12 on patterned substrate 10 receive a stampcomponent 30S from stamp posts 22 of stamp 20 although all of stampcomponents 30S are micro-transfer printed. The subset of substrate posts12 can be adjacent neighbors to each other, for example as shown inFIGS. 6B, 8B, 10, 12, 18 and 19, or the subset of substrate posts 12 canbe sampled within a patterned substrate 10 area.

In some embodiments, only a subset of components 30 adhered to stamp 20are transferred to substrate posts 12 in a micro-transfer print step sothat stamp components 30S not in the subset remain adhered to stampposts 22 of stamp 20 (e.g., as shown in FIGS. 4A-12). The subset ofcomponents 30 that are micro-transfer printed can be adjacent to eachother on stamp 20 and substrate posts 12 so that no components 30 not inthe subset are between micro-transfer printed components 30. In someembodiments, the subset of components 30 that are micro-transfer printedare not all adjacent to each other on stamp 20 so that components 30 notin the subset are between the micro-transfer printed components 30, forexample as illustrated in FIGS. 6B, 10, and 11, in which every othercomponent 30 on stamp 20 is transferred to substrate posts 12 in eachmicro-transfer print step. Micro-transfer printed components 30 onsubstrate posts 12 can be adjacent even if they are not adjacent onstamp 20, as illustrated in FIGS. 6B, 10, and 11 for example, so thatcomponents 30 on substrate posts 12 and patterned substrate 10 extendover a greater area than components 30 did on component source wafer 40(where the area can be the convex hull of components 30 over therespective surface). Thus, in some such embodiments, picked-up stampcomponents 30S on stamp 20 are separated by a distance in one or twodimensions by a stamp component separation distance 24 and substrateposts 12 are separated by a distance in one or two dimensions by asubstrate post separation distance 14 that is greater than stampcomponent separation distance 24, for example as shown in FIGS. 4A and4B.

As shown, substrate posts 12 can form a regular rectangular array ofsubstrate posts 12 on patterned substrate 10, but can, in general, bearranged in any desired pattern, including, for example, polygonscurves, circles, or a random arrangement.

In some embodiments, for example as shown in FIGS. 17A and 17B (andFIGS. 6B, 8B, 10, and 12), a micro-transfer printed substrate postcomponent 30P does not extend over an edge of a substrate post 12 onsubstrate surface 11 of patterned substrate 10. For example, a substratepost component 30P can have a component area 36 over the extent ofsubstrate post 12 equal to or smaller than a substrate post area 18 of asurface of substrate post 12 on which substrate post component 30P ismicro-transfer printed. An edge of substrate post component 30P can bealigned with an edge of a substrate post 12 on which substrate postcomponent 30P is micro-transfer printed, as shown in FIGS. 6B, 8B, 10,and 12, or can be spatially set back from a substrate post 12 edge, asshown in FIGS. 17A and 17B.

Referring to FIGS. 17A and 17B, substrate post components 30P can beadhered to substrate posts 12 with a patterned layer of adhesive 16, forexample coated on substrate post 12, or provided as a lamination, or byvan der Waals forces. As noted above, components 30 can comprise activecomponent circuits 34. Patterned substrate 10 can comprise substratecircuits 90 formed in, on, or disposed on patterned substrate 10 thatare electrically connected to the active circuits in components 30, asdescribed further below.

In some embodiments, any one or all of a component center, centroid, orcenter of mass (any one or more of which is referred to as componentcenter 32) of component 30 can be disposed over substrate post 12 sothat substrate post 12 is between component center, component centroid,or component center of mass 32 and patterned substrate 10. As usedherein, component center 32 refers to any one or more of a componentcenter, component centroid, and component center of mass. It isunderstood that in a given arrangement, a component center of mass maynot be in the same location as a center or centroid of the component. Insome embodiments, this arrangement can provide a robust mechanicalstructure that can help keep component 30 adhered to substrate post 12,especially when exposed to mechanical stress, such as vibration.

FIGS. 17A and 17B illustrate a substrate post component 30P that isdisposed completely within a substrate post area 18 of a surface of asubstrate post 12. In some embodiments, referring to FIGS. 18A and 18B,a micro-transfer printed substrate post component 30P on a substratepost 12 on substrate surface 11 of patterned substrate 10 extends overan edge of substrate post 12 in two dimensions. Printed structure 99comprises a patterned substrate 10 comprising a substrate surface 11 anda substrate post 12 protruding from substrate surface 11. Substrate post12 comprises a substrate post material. Component 30 has a component topside 38 and a component bottom side 39 opposite component top side 38.Component bottom side 39 is adhered to substrate post 12 and extendsover at least one edge of substrate post 12. In some embodiments, acomponent 30 comprises a component material different from a substratepost material. Component 30 can comprise a separated or broken (e.g.,fractured) component tether 53. In some embodiments, a component 30 isadhered or attached to a patterned substrate 10 and substrate post 12only by component bottom side 39.

In some embodiments, referring to FIGS. 19A-19C, a micro-transferprinted substrate post component 30P on a substrate post 12 extends overan edge of substrate post 12 in one dimension or direction and does notextend over an edge of substrate post 12 in an orthogonal dimension ordirection. In such embodiments, for example, a substrate post 12 canform a ridge with a length greater than a width that extends in a lengthdirection beyond a substrate post component 30P micro-transfer printedon substrate post 12 with component center 32 disposed over substratepost 12. Thus, according to some micro-transfer printed structureembodiments, substrate post component 30P extends over one side ofsubstrate post 12, extends over two sides of substrate post 12, extendsover four sides of substrate post 12, or extends over opposing sides ofsubstrate post 12.

As shown in FIGS. 19B and 19C, a component 30 (substrate post component30P) having a component circuit 34 has been micro-transfer printed ontoa substrate post 12 on substrate surface 11 of patterned substrate 10with component center 32 disposed over substrate post 12. The component30 has been electrically operated. In some embodiments, referring stillto FIGS. 19B and 19C, by disposing a substrate post component 30P withan edge extending over an edge of substrate post 12, the extendingportion of substrate post component 30P can vibrate, for exampleoperating in an acoustic wave transducer 94, for example in a bulk orsurface acoustic wave filter or sensor, while a center portion ofsubstrate post component 30P is adhered to substrate post 12 to supportsubstrate post component 30P. In some embodiments, component 30 cancomprise acoustic mirrors having a speed of sound transmission differentfrom the speed of sound transmission in other component 30 material.Acoustic mirrors can be, for example, disposed on component top side 38,component bottom side 39, or both. In some embodiments, such acousticwave mirrors are unnecessary, since the length-wise ends of component 30are not adhered to any structure and are free to vibrate withoutdisturbing other structures, for example without disturbing patternedsubstrate 10, thereby providing a simpler and more efficient acousticwave transducer 94 structure (e.g., in an acoustic wave filter orsensor) that is easier and less expensive to construct.

In some embodiments, components 30 are adhered to a stamp post 22 of astamp 20 and transferred to a substrate post 12, for example by van derWaals forces. The adhesion between a component 30 and a surface of stamppost 22 can be dependent, at least in part, on the area of component 30that is in contact with stamp post 22, for example a distal end of stamppost 22. Similarly, the adhesion between a surface of a substrate post12 and a component 30 micro-transfer printed to substrate post 12 can bedependent, at least in part, on the area of component 30 that is incontact with substrate post 12, for example a distal end of substratepost 12. In some embodiments, in order to micro-transfer print acomponent 30 from a stamp post 22 to a substrate post 12, an adhesionbetween component 30 and substrate post 12 must be greater than anadhesion between component 30 and stamp post 22. Thus, it can be helpfulif the area of substrate post 12 surface to which component 30 ismicro-transfer printed is at least as large, or larger than, the area ofstamp post 22 from which component 30 is micro-transfer printed. In someembodiments, in which substrate post area 18 of substrate post 12 islarger than component area 36 of component 30, the difference in stamppost area 26 and substrate post area 18 is not necessarily significant,since an adhesion area for each can be the same (component area 36 ofcomponent 30), for example as shown in FIGS. 17A, 17B. However, in acase in which component 30 extends over an edge of substrate post 12 andis likely to have a component area 36 greater than substrate post area18, it can be helpful to employ a stamp post 22 with a stamp post area26 in contact with component 30 that is equal to or less than substratepost area 18 that is in contact with component 30 during micro-transferprinting, so that a stamp 20 adhesion area in contact with component 30is equal to or less than substrate post 12 adhesion area in contact withcomponent 30. Moreover, if component 30 extends over an edge ofsubstrate post 12 and a stamp post 22 likewise extends over substratepost 12 edge, when component 30 is transfer printed to substrate post12, stamp 20 can press against component 30 on a portion of component 30that is not supported by substrate post 12, possibly bending or breakingcomponent 30. Referring to FIGS. 20A and 20B, stamp 20 has a stamp post22 with a stamp post area 26 on the distal end of stamp post 22 that issubstantially equal (at least within manufacturing tolerances) tosubstrate post area 18 of substrate post 12. Thus, the area of component30 in contact with stamp post 22 is equal to the area of component 30 incontact with during micro-transfer printing substrate post 12 (substratepost area 18). Accordingly, in some embodiments, stamp 20 comprises astamp post 22 and stamp post 22 has a dimension W (e.g., a width)substantially the same as a corresponding dimension W of substrate post12.

In some embodiments, a substrate post 12 extends over substrate surface11 of patterned substrate 10 to form a ridge that has a length greaterthan a dimension of component 30, for example a substrate post lengthalong substrate surface 11 greater than a width W of component 30, asshown in FIG. 21, in which the length L of component 30 is orientedorthogonally to the length of substrate post 12. In some suchembodiments, more than one component 30 can be printed on a single ridgeor substrate post 12. Thus, if a component 30 is a first component 30adhered to a substrate post 12, printed structure 99 can comprise asecond component 30 adhered to substrate post 12. The ridge (substratepost 12) can have a substrate post top side 19 opposite patternedsubstrate 10 to which a component bottom side 39 of a component 30 isadhered. In some embodiments, a substrate post 12 extends in a straightline and has a rectangular cross section parallel to surface 11 ofpatterned substrate 10. In some embodiments, a substrate post 12 extendsin one or more directions and can form a square, rectangle, curve,circle, ellipse, polygon, U-shape, X-shape, or other arbitrarycollection of connected line segments or curved segments over substratesurface 11. In some embodiments, a component 30 is micro-transferprinted to two or more substrate posts 12.

Referring further to FIG. 21, a printed structure 99 in accordance withsome embodiments can comprise electrical conductors disposed onsubstrate surface 11 of patterned substrate 10, forming a substrateelectrode 66. In some embodiments, electrical conductors can be disposedon substrate post 12, forming a substrate post electrode 64. In someembodiments, substrate post 12 can be electrically conductive and canconduct one or more of electrical power, ground, and signals. Substrateelectrodes 66 can be electrically connected to substrate post electrodes64 and substrate post electrodes 64 can be electrically connected tocomponents 30, for example through component electrodes 61 on components30, to provide electrical power and control signals to operatecomponents 30. Thus, a printed structure 99 according to someembodiments, can comprise one or more substrate post electrodes 64 onsubstrate post top side 19. A component 30 can be electrically connectedto the one or more substrate post electrodes 64.

In some embodiments of the present disclosure, components 30 can haveone or more component electrodes 61 on a component top side 38 ofcomponents 30 opposite substrate post 12 (component top electrodes 60)or components 30 can have one or more component electrodes 61 on acomponent bottom side 39 of components 30 (e.g., as shown in FIG. 18B)adjacent to substrate post 12 (component bottom electrodes 62), as shownin FIGS. 22A and 22B, or both. Component top and bottom electrodes 60,62 can be electrically connected to substrate post electrodes 64 andthen to substrate electrodes 66. In some embodiments of the presentdisclosure, component bottom electrodes 62 can be congruent withsubstrate post electrodes 64. Component top and bottom electrodes 60, 62can be referred to collectively or individually as component electrodes61.

Referring to FIG. 21, two components 30 each having two component topelectrodes 60 electrically connected to substrate post electrodes 64 aredisposed on substrate post 12. Components 30 are electrically connectedin series through component top electrodes 60 but can be connected inany desired fashion or combination of series and parallel electricalconnections in various embodiments. Each component 30 is alsoelectrically connected through a component bottom electrode 62 (notvisible in FIG. 21) to a substrate post electrode 64. Substrate postelectrodes 64 are electrically connected to substrate electrodes 66 onpatterned substrate 10.

In some embodiments illustrated with the perspectives of FIGS. 22A, 23Aand cross sections of FIGS. 22B, 23B taken along cross section lines A,a component 30 disposed on substrate post 12 has a single component topelectrode 60 and a single component bottom electrode 62, eachelectrically connected on opposite sides of substrate post 12 to asubstrate post electrode 64. Substrate post electrodes 64 areelectrically connected to substrate electrodes 66. In FIGS. 22A and 22B,substrate electrodes 66 are electrically connected to a substratecircuit 90 on patterned substrate 10. Substrate circuit 90 can be anelectronic circuit that electrically controls, operates, providessignals to, or receives signals from component 30 through substrateelectrodes 66, substrate post electrodes 64, and component top andbottom electrodes 60, 62.

The embodiments illustrated in FIGS. 21, 22A, and 22B have component topelectrodes 60 electrically connected to component 30 through a componentelectrode 61 or other electrical connection that is relatively smallcompared to a component surface extent of component 30 (component area36, for example as shown in FIGS. 17A, 17B). Such embodiments can beuseful in applications in which component 30 is responsive to electricalcurrents provided by component top and bottom electrodes 60, 62, forexample when components 30 comprise electronic or opto-electronicdevices or circuits. In the embodiments illustrated in FIGS. 23A, 23B,component top and bottom electrodes 60, 62, extend over much orsubstantially all of the top and bottom surfaces of component 30,respectively (e.g., component top side and component bottom side 38, 39,for example as shown in FIG. 18B). Such embodiments can be useful inapplications in which component 30 is responsive to an electrical fieldprovided by component top and bottom electrodes 60, 62, for example whencomponents 30 comprise piezo-electric material. Structures in accordancewith FIGS. 23A and 23B have been constructed and demonstrated to haveresonant modes at desirable frequencies.

FIGS. 21, 22A and 22B, 23A and 23B, 25A and 25B, and 26, illustrate avariety of embodiments in which any combination of one, two, or morecomponent top electrodes 60, component bottom electrodes 62, substratepost electrodes 64, and substrate electrodes 66 are used to providepower and/or ground connections and/or provide and receive electricalsignals to operate, control, or respond to components 30. Components 30can each be disposed on a single substrate post 12 (e.g., as shown inFIGS. 19A-19C), multiple components 30 can be disposed on a singlesubstrate post 12 (e.g., as shown in FIGS. 21 and 26), or a component 30can be disposed on multiple substrate posts 12 (not shown). In any case,components 30 can operate individually or can be electrically connectedto form a circuit.

In some embodiments, referring to FIG. 22C, printed structures 99comprise solder 68 disposed between a substrate post 12 and a component30 to improve an electrical connection between a component bottomelectrode 62 and a substrate post electrode 64. In a method inaccordance with certain embodiments, solder 68 is heated and cooled toelectrically connect a substrate post electrode 64 on substrate post 12to a component bottom electrode 62 on a component 30.

As also shown in FIG. 22C, in some embodiments, a component topelectrode 60 is wire bonded to a substrate post electrode 64 or asubstrate electrode 66 with a wire bond 69 wire and a method compriseswire bonding a wire to electrically connect a component top electrode 60on component 30 to a substrate post electrode 64 or to a substrateelectrode 66 (e.g., as shown in FIG. 22D). A wire bond 69 can alsoelectrically connect a substrate post electrode 64 to a substrateelectrode 66. Thus, printed structures 99, according to someembodiments, comprise a wire bond 69 electrically connected to at leastone of the one or more component top electrodes 60 or comprise asubstrate post electrode 64 disposed on a substrate post 12 and a wirebond 69 electrically connected to substrate post electrode 64, or both.

In some embodiments, component 30 comprises a piezo-electric material.Component 30 can be at least a portion of a piezo-electric transducer orpiezo-electric resonator. For example, component 30 can be used in anacoustic wave filter or sensor, such as a bulk acoustic wave filter orsensor or a surface acoustic wave filter or sensor. For example, in someembodiments in which component top and bottom electrodes 60, 62 extendover a substantial portion of component top and bottom sides 38, 39 ofcomponent 30, respectively, component top and bottom electrodes 60, 62can provide an electrical field in component 30 that, when controlled ata suitable frequency can cause resonant mechanical vibrations incomponent 30 such that the component and electrodes serve as an acousticwave transducer 94. In some embodiments, a component top electrode 60and a component bottom electrode 62 are provided on component top andbottom sides 38, 39, respectively, to form a two-electrode acoustic wavefilter (e.g., as shown in the perspective of FIG. 23A and correspondingcross section of FIG. 23B taken across cross section line A of FIG.23A). In some embodiments, two component top electrodes 60 and twocomponent bottom electrodes 62 are provided on component top and bottomsides 38, 39, respectively, to form a four-electrode acoustic wavefilter, for example as shown in FIG. 23C. Two component top electrodes60 can be interdigitated, for example as shown in FIG. 23D, or twocomponent bottom electrodes 62 can be interdigitated, or both. FIG. 23Eillustrates another arrangement of component top and bottom electrodes60, 62. In some embodiments, because one or more ends of component 30are not adhered to a surface and are free to move, resonant frequenciesof mechanical vibration in component 30 can be controlled and a highquality (high Q) acoustic wave transducer 94 (or filter) is provided.Various arrangements and patterns of component top and bottom electrodes60, 62 can be used in various embodiments and can implement bulk orsurface acoustic wave transducers 94 (e.g., in bulk or surface acousticwave filters, respectively) with a corresponding variety of resonantmodes in component 30 using two, three, four or more componentelectrodes 61. A printed structure 99 corresponding to FIGS. 19A-19C and22A-22B has been constructed and operated.

Referring to FIGS. 24A-24C, in some embodiments according to the presentdisclosure, components 30 can have a variety of shapes and form factors,for example a rectangular form factor commonly used for integratedcircuits, as shown in FIG. 24A. In some embodiments, for example wherecomponents 30 are used in acoustic transducers, various component 30shapes can be useful, for example circular or disc-shaped (FIG. 24B) orx-shaped, cross-shaped, or the shape of a plus sign (FIG. 24C). Ingeneral, according to some embodiments, components 30 can have anyuseful shape in either two dimensions or three dimensions. Such shapescan be useful, for example in enabling vibrational resonance modes foracoustic devices.

Referring to FIGS. 25A and 25B, an exploded view of a singlemicro-transfer printed component 30 with a separated or broken (e.g.,fractured) component tether 53 illustrates component bottom electrodes62 aligned with substrate post electrodes 64 on substrate post 12 (shownin FIG. 25A) or multiple substrate posts 12 (shown in FIG. 25B).Substrate post electrodes 64 are electrically connected to substrateelectrodes 66 on substrate surface 11 of patterned substrate 10. FIG. 26illustrates two of the micro-transfer printed components 30 withseparated or broken (e.g., fractured) component tethers 53 shown inFIGS. 25A, 25B disposed on a single substrate post 12 with a singlesubstrate post electrode 64 electrically connected to a substrateelectrode 66 on substrate surface 11 on patterned substrate 10.

Referring to FIG. 26, in some embodiments, a printed structure 99includes a micro-transfer printable module structure 98 (also referredto as module 98) that can be printed or placed on a destinationsubstrate such as a printed circuit board (PCB). Such a module 98 can beconstructed on, for example, a semiconductor wafer with sacrificialportions 82 and anchors 50 and module tethers 92 connecting modules toanchors 50 (e.g., similar to FIG. 1B with component tethers 52). (Moduletethers 92 connecting modules 98 to a wafer are said to each be at leasta portion of a module tether 92). A method can comprise printing (e.g.,micro-transfer printing) a module 98 to a destination substrate. (Moduletethers 92 that are broken or separated as a result of printing are saidto each be at least a portion of a module tether 92.)

According to some embodiments and referring to FIGS. 27 and 28, a modulestructure 98 comprises a patterned substrate 10 having a substratesurface 11 and a substrate post 12 protruding from the substrate surface11 or a layer provided on substrate surface 11. A component 30 isdisposed on the substrate post 12. Component 30 has a component top side38 and a component bottom side 39 opposite component top side 38.Component bottom side 39 is adhered to substrate post 12 and component30 extends over at least one edge of substrate post 12. Component 30 canbe adhered or attached to patterned substrate 10 or substrate post 12only on component bottom side 39.

Referring still to FIGS. 27 and 28, one or more component electrodes 61are disposed on component 30 (e.g., as shown in FIG. 22B). The one ormore component electrodes 61 can comprise a component top electrode 60disposed on component top side 38, a component bottom electrode 62disposed on component bottom side 39, or both. Component top electrodes60 and component bottom electrodes 62 are generically referred to ascomponent electrodes 61.

In some embodiments, module structure 98 comprises a cavity 70 formed ordisposed in or on substrate surface 11 of patterned substrate 10. Cavity70 can have a cavity floor 72 (for example, congruent with substratesurface 11 in cavity 70) and cavity walls 74. Substrate post 12 can bedisposed on cavity floor 72. In some embodiments, module structure 98comprises a cap 76 disposed over cavity 70 to substantially orcompletely surround or enclose cavity 70. In some embodiments, cap 76can have a small opening through cap 76 so that cavity 70 is notcompletely sealed. In some embodiments, cavity walls 74 are formed onsubstrate surface 11 of patterned substrate 10 and cap 76 is adhered tocavity walls 74, for example with a patterned layer of adhesive 16(e.g., as shown in FIG. 27). In some embodiments, cavity walls 74 areformed on cap 76 and adhered to substrate surface 11 of patternedsubstrate 10, for example with a patterned layer of adhesive 16 (e.g.,as shown in FIG. 28).

In some embodiments, component 30 is micro-transfer printed from acomponent source wafer 40 and includes a separated or broken (e.g.,fractured) component tether 53. In some such embodiments, component 30can be adhered to substrate post 12, for example with a patterned layerof adhesive 16 (e.g., as shown in FIGS. 17A, 17B where adhesive 16 ispatterned to be disposed only on substrate posts 12). In someembodiments, component 30 is not micro-transfer printed and can be, forexample, constructed in place using photolithographic techniques.Similarly, in some embodiments, cap 76 is micro-transfer printed from acap source wafer and includes a separated or broken (e.g., fractured)cap tether 78. In some embodiments, cap 76 is not micro-transfer printedand can be, for example, laminated over cavity 70. According to someembodiments, a printed structure 99 includes a module 98 that can be oris printed or placed on a destination substrate, such as a printedcircuit board (PCB) for example. In some embodiments, a module 98 can beconstructed on, for example, a semiconductor wafer with sacrificialportions 82 and anchors 50 and module tethers 92 connecting modules toanchors 50 (as shown in FIGS. 29 and 30, discussed below). A method cancomprise micro-transfer printing such a module structure 98 module to adestination substrate. In some embodiments, module structure 98 is notmicro-transfer printable or micro-transfer printed and can be, forexample, constructed in place using photolithographic techniques.

According to some embodiments, two or more substrate posts 12 aredisposed within cavity 70 or two or more components 30 are disposedwithin cavity 70, or both. In some embodiments, a substrate post 12within cavity 70 can have two or components 30 disposed on eachsubstrate post 12, for example as discussed above with respect to FIG.26. According to some embodiments, one or more component electrodes 61of the two or more components 30 disposed within cavity 70 areelectrically connected, for example a component top or bottom electrode60, 62 of a first component 30 is electrically connected to a componenttop or bottom electrode 60, 62 of a second component 30, where first andsecond components 30 are both disposed within a common cavity 70 and canbe, but are not necessarily, disposed on a common substrate post 12,e.g., to form a common circuit.

Module structure 98 can comprise component top and bottom electrodes 60,62 on opposing component top and bottom sides 38, 39 of component 30,for example as shown in FIGS. 27 and 28 or in FIGS. 23A-23D. Asdescribed with respect to FIGS. 23A-23D, component top and bottomelectrodes 60, 62 can be electrically connected to respective substratepost electrodes 64 and substrate electrodes 66 to receive or provide anelectrical power or ground or control or information signals. Substrateelectrodes 66 can extend beyond cavity 70 and can be controlled bydevices external to cavity 70, for example be extending along substratesurface 11.

In some embodiments, patterned substrate 10 is a semiconductor substrateand comprises an electronic substrate circuit 90 (FIGS. 17A-17B,22A-22D). Electronic substrate circuit 90 can be electrically connectedthrough substrate electrodes 66, substrate post electrodes 64, andcomponent top and bottom electrodes 60, 62 to control, provide signalsto, or respond to component 30. Substrate circuit 90 can extend beyondcavity 70 and can interface with devices external to cavity 70, forexample be extending along substrate surface 11.

In some embodiments, component 30 comprises a component materialdifferent from the substrate post material. In some embodiments, thecomponent material can be the same as or substantially similar to thesubstrate post material. A substrate post material can be a dielectric,can comprise conductors (e.g., substrate post electrodes 64), or can bea conductor (e.g., a metal). A component material can be or include oneor more of a semiconductor, a compound semiconductor, a III-Vsemiconductor, a II-VI semiconductor, or a ceramic (e.g., a syntheticceramic). For example, a component material can be or include one ormore of GaN, AlGaN, AlN, gallium orthophosphate (GaPO₄), Langasite(La₃Ga₅SiO₁₄), lead titanate, barium titanate (BaTiO₃), lead zirconatetitanate (Pb[Zr_(x)Ti_(1-x)]O₃ 0≤x≤1), potassium niobate (KNbO₃),lithium niobate (LiNbO₃), lithium tantalate (LiTaO₃), sodium tungstate(Na₂WO₃), Ba₂NaNb₅O₅, Pb₂KNb₅O₁₅, zinc oxide (ZnO), Sodium potassiumniobate ((K,Na)NbO₃) (NKN), bismuth ferrite (BiFeO₃), Sodium niobate(NaNbO3), bismuth titanate (Bi₄Ti₃O₁₂), sodium bismuth titanate(Na_(0.5)Bi_(0.5)TiO₃), wurtzite, and polyvinylidene fluoride. Acomponent material can be or include a piezo-electric material thatexhibits a piezo-electric effect. In some embodiments, component 30 canbe processed or formed using photolithographic methods.Photolithographic methods and materials are also useful to formcomponent top and bottom electrodes 60, 62 (component electrodes 61) andany component circuit 34.

Referring to FIGS. 29 and 30, some embodiments can comprise a modulesource wafer 80 comprising a sacrificial layer 81 having one or moresacrificial portions 82 separated by anchors 50. The sacrificial layer81 can be patterned. One or more sacrificial portions 82 aredifferentially etchable from module source wafer 80 and patternedsubstrate 10 is disposed at least partially on one of the one or moresacrificial portions 82. Substrate 10 can extend beyond sacrificialportion 82 to form a portion of anchor 50 and can also form at least apart of module tether 92 (and in some embodiments with a micro-transferprintable component 30, a component substrate can similarly form a partof a component tether 52). In some embodiments, a material ofsacrificial portion 82 is a material different from module source wafer80 or is an anisotropically etchable material. Sacrificial layer 81 cancomprise a same anisotropically etchable material as module source wafer80. As shown in FIG. 30, once sacrificial portion 82 is etched, a gap 84(indicated by a double-ended arrow) is defined. Once module structure 98is removed from module source wafer 80 (for example with transfer device20 such as a viscoelastic stamp), module tether 92 is broken (e.g.,fractured) or separated (e.g., is at least a portion of a module tether92).

According to some embodiments and referring to FIG. 31, a method ofmaking a module structure 98 comprises providing a patterned substrate10 having a substrate surface 11 and a substrate post 12 protruding fromsubstrate surface 11 or a layer disposed on substrate surface 11 in step200. In step 210, a component 30 is disposed on substrate post 12,component 30 having a component top side 38 and a component bottom side39 opposite component top side 38. Component bottom side 39 is disposedon substrate post 12 and component 30 extends over at least one edge ofsubstrate post 12, forming a module structure 98. One or more componentelectrodes 61 are disposed on component 30. In step 220, a cap 76 isdisposed over component 30 and patterned substrate 10 to enclosecomponent 30 in a cavity 70. In optional step 230, module structure 98is encapsulated and in optional step 240, module structure 98 ismicro-transfer printed.

In some embodiments, providing component electrodes 61 can compriseproviding a component top electrode 60 disposed on component top side38, providing a component bottom electrode 62 disposed on componentbottom side 39, or both.

In some embodiments, a substrate is patterned to form a patternedsubstrate 10 and substrate post 12, for example a glass or polymersubstrate patterned using photolithographic methods and materials.

In some embodiments and referring to FIG. 32, component 30 is providedin step 210 by micro-transfer printing component 30 from componentsource wafer 40 to substrate post 12 (step 212). In some embodiments, acavity 70 is provided in or on a substrate (e.g., patterned substrate10), cavity 70 having a cavity floor 72 and cavity walls 74. In someembodiments, cavity 70 is provided by micro-transfer printing a cap 76comprising cavity walls 74 from a cap source wafer to substrate surface11 or a layer on substrate surface 11 of patterned substrate 10 as shownin FIG. 28) in step 222.

In some embodiments and referring to FIG. 33A, cavity 70 is provided byforming cavity walls 74 on substrate surface 11 or a layer on substratesurface 11 of patterned substrate 10 in step 202 as part of formingpatterned substrate 10, for example using photolithographic materialsand processes (e.g., as shown in FIG. 27). Component 30 can then beprovided in step 212, for example by micro-transfer printing component30 from component source wafer 40 to substrate post 12 and cap 76 bymicro-transfer printing or laminating cap 76 to cavity walls 74 in step225. In some embodiments, referring to FIG. 33B, a component 30 withpatterned substrate 10 and substrate post 12 is micro-transfer printedto a substrate post 12 to form a module 98. Side walls that serve ascavity walls 74 can be provided either with cap 76 or with patternedsubstrate 10. In either case, module 98 can be micro-transfer printed toa cap 76 in step 226. As illustrated in FIG. 33C, a sacrificial portion82 on which a module 98 is disposed can be etched so that module 98 canbe picked up by a pick-up stamp 20 in step 227, transferred to a printstamp 20 in step 228, and printed to a cap 76 in step 229. A similarprocess can be used to micro-transfer print a cap 76. Referring to FIG.34, in some embodiments, cavity walls 74 are formed in step 224 aftercomponent 30 is provided in step 212 by micro-transfer printingcomponent 30 from component source wafer 40 to substrate post 12, forexample using photolithographic techniques.

As described with respect to FIGS. 31-34, in some embodiments, component30 can be provided by micro-transfer printing. In some embodiments,component 30 is constructed or formed on or over a substrate 10 or layerdisposed on substrate 10. Referring to FIG. 35, a substrate 10 can beprovided in step 206, a component 30 formed over, on, or in substrate 10in step 214, and an optional etch-mask layer provided and patterned instep 216. In step 218, substrate 10 is etched to form patternedsubstrate 10 with cavity walls 74 and substrate post 12, providingmodule structure 98.

Methods according to certain embodiments are described in more detail inFIGS. 36A-36L. Referring to FIG. 36A, a substrate, for example a modulesource wafer 80, is provided with a sacrificial layer 81 definingsacrificial portions 82 laterally separated by anchors 50. A substrate10 is disposed over sacrificial portions 82 and optionally over anchors50. Substrate 10 is differentially etchable from sacrificial portions82. The portions of substrate 10 between sacrificial portions 82 can beconsidered a part of anchors 50 (as shown in FIG. 36B). Substrate 10 cancomprise any of a wide variety of materials suitable as a lithographicsubstrate, for example including one or more of glass, polymer, and asemiconductor.

For clarity, FIGS. 36C-36J are details of an individual sacrificialportion 82 (with anchors 50 not shown for simplicity). Referring to FIG.36C, cavity layer 56 is disposed over substrate 10 and patterned (asshown in FIG. 36D), for example by etching, to form a cavity 70 withcavity walls 74 and a cavity floor 72 with a post layer 57 of material(from cavity layer 56) on patterned substrate 10. Cavity layer 56 can beor comprise, for example, a resin, oxide, or nitride, for example thatcan be patterned using photolithographic methods. Optional electrodescan be deposited and patterned, and an optional seed layer can beprovided on post layer 57 in cavity 70.

Referring next to FIG. 36E, a component layer 58 of material (e.g., alayer of semiconductor or piezo-electric material) is blanket depositedand patterned (as shown in FIG. 36F) and can be further processed toform component 30. An etch-stop layer 86, for example a dielectric, isdeposited (as shown in FIG. 36G) and patterned (as shown in FIG. 36H),exposing patterned substrate 10 and only a portion of post layer 57,using photolithographic methods. The exposed portion of post layer 57 isthen etched to form substrate post 12 on cavity floor 72 betweencomponent 30 and substrate surface 11 of patterned substrate 10 (asshown in FIG. 36I). At any point after component material is deposited,component electrodes 61 (shown in FIG. 22B) can be formed on component30. As shown in FIG. 36J, a cap 76 can then be disposed over (e.g.,laminated or micro-transfer printed to) cavity walls 74 to encapsulatemodule 98.

FIGS. 36K and 36L are less detailed than FIGS. 35A-35J and show twomodules 98 on a module source wafer 80. Each module 98 is disposedentirely over a sacrificial portion 82 and the modules 98 are attachedto anchors 50 by module tethers 92 (as shown in FIG. 36K) (e.g., moduletethers 92 are each at least a portion of a module tether 92). As shownin FIG. 36L, sacrificial portions 82 are etched to form gaps 84(indicated by a double-ended arrow) over which each module 98 issuspended. Sacrificial portions 82 can be anisotropically etchableportions of module source wafer 80 or a layer of material that isdifferentially etchable from module source wafer 80 and patternedsubstrate 10. Modules 98 are attached to anchors 50 only with moduletethers 92. An encapsulation layer 79 encapsulates the module 98 andforms module tethers 92. Encapsulation layer 79 can be, for example, anoxide or nitride such as silicon dioxide or silicon nitride.Encapsulation layer 79 can be, for example, a polymer. Thus, referringstill to FIG. 36L, modules 98 are ready to be micro-transfer printed bya micro-transfer printing stamp 20.

According to some embodiments and with reference to FIGS. 37A-37C,methods of constructing modules 98 can comprise providing a modulesource substrate 80 with a patterned sacrificial portion 82 on which apatterned substrate 10 is provided and a substrate post 12 disposed(shown in FIG. 37A). Referring to FIG. 37B, a component 30 with (orwithout) component electrodes 61 (e.g., component top electrodes 60) anda separated or broken (e.g., fractured) component tether 53 ismicro-transfer printed onto substrate post 12. Additional processing canbe provided to electrically connect component electrodes 61 (e.g.,component top electrodes 60 or component bottom electrodes 62, or both)to substrate electrodes 66 (not shown in FIG. 37B, see FIGS. 22A, 22Bfor example). As shown in FIG. 37C, a cap 76 is provided over component30 to provide cavity 70, for example by micro-transfer printing cap 76with separated or broken (e.g., fractured) cap tether 78 to patternedsubstrate 10. FIG. 38 is a less detailed cross section of modulestructure 98 in FIG. 37C provided on a module source wafer 80 withsacrificial portions 82 laterally separated by anchors 50 connected tomodules 98 with module tethers 92. FIG. 38 also illustrates a substratecircuit 90 formed on or in substrate 10 and electrically connected tocomponent 30 through substrate electrodes 66. Fractured cap tether 78can be present, for example if cap 76 is micro-transfer printed tosubstrate 10 (as shown in FIG. 38) or is not present, for example, ifcap 76 is formed on substrate 10. Once sacrificial portions 82 areetched, module 98 can be micro-transfer printed, for example with aviscoelastic stamp 20.

In some embodiments, referring to FIGS. 39A-39H, components 30 can beprovided on a component source wafer 40 (shown in FIG. 39A), optionalstructures such as component electrodes 61 (shown in FIG. 39B) orsubstrate posts 12 (not shown) formed on components 30, a patternedsacrificial layer 81 disposed over components 30 (shown in FIG. 39C), alayer of adhesive 16 provided on sacrificial layer 81 (shown in FIG.39D) to adhere a carrier substrate 17 to sacrificial layer 81 (shown inFIG. 39E), component source substrate 40 removed to expose component 30and at least a portion of sacrificial layer 81 (shown in FIG. 39F), forexample by laser lift-off or grinding. Optional structures such ascomponent electrodes 61 (shown in FIG. 39G) can be formed on components30 and at least a portion of sacrificial layer 81 removed (shown in FIG.39H) to prepare component 30 for micro-transfer printing. Componentelectrodes 61 can be component top electrodes 60 or component bottomelectrodes 62 or both. In some embodiments, sacrificial layer 81 isetched to form a component tether 52 attaching component 30 to an anchor50 of the layer of adhesive 16, and component 30 micro-transfer printed.Component 30 can comprise a semiconductor or piezo-electric material.The process described in FIGS. 39A-39H enables the construction ofstructures on both sides of component 30, for example any one or more ofcomponent electrodes 61, dielectric structures, substrate posts 12,component circuits 34, and optical structures.

Referring to FIGS. 40-48, in some embodiments, a printed structure 99comprises an acoustic wave transducer 94 comprising component 30 andcomponent electrodes 61 disposed on component 30, and connection posts67 attached (e.g., directly or indirectly) to and extending away fromcomponent 30 or layers on component 30. Connection posts 67 can extendaway from component bottom side 39 (shown in FIG. 18B) and can be indirect contact with component 30 or one or more layers in contact withcomponent 30. Each component electrode 61 (e.g., either a component topor a component bottom electrode 60, 62, for example as shown in FIG.22B) is electrically connected to a connection post 67. A connectionpost 67 is an electrically conductive structure that extends away andprotrudes from component 30 or a layer in contact with component 30. Aconnection post 67 can have a base on a proximal end of connection post67 that has a larger area than a distal end of connection post 67 sothat connection post 67 can have a sharp or pointed distal end orstructure able to extend into or penetrate an electrical substrateelectrode 66 on a substrate 10 when component 30 is micro-transferprinted to the substrate, for example patterned substrate 10, forexample as shown in FIGS. 43 and 45. In some embodiments, patternedsubstrate 10 is patterned with substrate electrodes 66 disposed onsubstrate surface 11 of patterned substrate 10, component 30 is disposedon substrate surface 11, and each connection post 67 is in electricalcontact with a substrate electrode 66. Substrate electrodes 66 cancomprise a layer of solder to facilitate electrical connection betweeneach substrate electrode 66 and connection post 67. Patterned substrate10 can be a semiconductor substrate and can comprise electronicsubstrate circuit 90, as shown in FIGS. 47 and 48. Thus, substratecircuit 90 can be electrically connected to component 30 throughcomponent electrodes 61, connection posts 67, and substrate electrodes66 and, in some embodiments, can operate, control, send signals to, orreceive signals from component 30. Each bottom component electrode 62can be electrically connected to one or more connection posts 67.

Referring to the perspectives of FIGS. 40 and 41, component 30 connectedto separated or broken (e.g., fractured) component tether 53 has two ormore connection posts 67 (shown in FIG. 40) or four or more connectionposts 67 (shown in FIG. 41) extending from a component electrode 61(e.g., a component bottom electrode 62) with a sharp point. In someembodiments (not shown), component 30 can have 3 connection posts 67.Referring to FIG. 42, a plan view illustrates component 30 with fourconnection posts 67 on a single substrate post 12. Single substrate post12 is disposed under component 30 and component 30 extends over twoedges of single substrate post 12. Referring to the cross section ofFIG. 43, component 30 is micro-transfer printed so that connection posts67 extend into or penetrate (e.g., pierce) electrical substrateelectrodes 66 to make an electrical contact between component 30 andsubstrate electrodes 66. Component 30 can be adhered to patternedsubstrate 10 with a patterned layer of adhesive 16 that forms asubstrate post 12.

As shown in FIGS. 40-43, connection posts 67 are disposed near componentcenter 32 of component 30 (shown in FIGS. 19A-19C), for example nofurther from component center 32 than one quarter (e.g., one quarter,one fifth, one eighth, one tenth, or one twentieth) of the length ofcomponent 30, where component 30 has a length greater than a width overpatterned substrate 10, so that the distance between each connectionpost 67 and component center 32 is no more than one quarter of thelength (e.g., no more than one quarter of the length, no more than onefifth of the length, no more than one eighth of the length, no more thanone tenth of the length, no more than one twentieth of the length). Insome embodiments, each of a plurality of connection posts 67 (e.g.,every connection post 67) is closer to component center 32 than an edgeof component 30. By disposing connection posts 67 closer to componentcenter 32 of component 30, for example, if component 30 is or comprisesa piezo-electric material, the ends of component 30 can vibrate in adirection orthogonal to substrate surface 11 of patterned substrate 10,for example providing bulk acoustic wave resonant modes in component 30and for example as shown in FIGS. 23A-23C. In other resonant modes, thecomponent 30 vibrates longitudinally, for example becomes longer andshorter in a lengthwise direction. In some embodiments, both vibrationalmodes are present in component 30 when it is in operation.

As shown in FIGS. 44-45, connection posts 67 are disposed near alength-wise end of component 30, for example farther from componentcenter 32 than one quarter of the length of component 30, wherecomponent 30 has a length greater than a width over patterned substrate10, so that the distance between connection posts 67 and componentcenter 32 is greater than one quarter the length. By disposingconnection posts 67 farther from the center of component 30, forexample, the center of component 30 can vibrate in a direction parallelto substrate surface 11 of patterned substrate 10 (a longitudinaldirection), providing surface acoustic wave resonant modes in component30.

Referring to FIGS. 43 and 45, component 30 can be adhered to patternedsubstrate 10 with a layer of patterned and cured adhesive 16 (e.g.,forming one or more substrate posts 12). Only a portion of component 30is adhered to patterned substrate 10 so that, if component 30 is part ofan acoustic wave transducer (e.g., used in an acoustic wave filter orsensor), component 30 is free to mechanically vibrate in desiredresonant modes and directions. In particular, ends of component 30 arefree to oscillate vertically, horizontally, or both, enabling additionaland stronger resonant modes. In some embodiments, components 30 aresmaller in any one or more of length, width, and thickness than otherprior-art devices and therefore can have fewer and stronger resonantmodes.

In some embodiments, a layer of adhesive 16 can be deposited andpatterned by inkjet printing. In some embodiments, a layer of adhesive16 is deposited, component 30 is micro-transfer printed onto the layerof adhesive 16, the layer of adhesive 16 is pattern-wise cured, forexample at the locations of the connection posts 67, and the remainingadhesive 16 removed, for example by stripping, washing, or etching theuncured adhesive 16, or by etching a support layer and undercuttingcomponent 30 as shown in FIGS. 36H and 36I.

Referring to FIGS. 46A and 46B, a micro-transfer printable component 30with connection posts 67 can be constructed by providing a componentsource wafer 40 with a sacrificial layer 81 comprising sacrificialportions 82 laterally separated by anchors 50. Sacrificial portions 82are differentially etchable from anchor 50 or can be an anisotropicallyetchable material. Depressions (e.g., pits, holes, or pyramidalstructures) are etched into sacrificial portions 82, one for eachconnection post 67. The shape of the etched depression and correspondingconnection posts 67 can have planar faces separated by sharp, linearedges and can be a pyramidal shape, for example if sacrificial portion82 comprises a crystalline structure and is anisotropically etchable(for example comprising a crystalline silicon material). The edges ofthe forms (and connection posts 67) can be planar, for example ifconnection post forms are made by etching crystalline materials. A metallayer is deposited over sacrificial portions 82 (for example byevaporation or sputtering) and the depressions and patterned to form aseparate electrical conductor for each connection post 67 that extendsinto sacrificial portion 82, for example using photolithographic methodsand materials. A substrate 88, e.g., a dielectric substrate, isdeposited and patterned over the electrical conductors, for example bycoating, evaporation, or sputtering and photolithographic patterning) sothat substrate 88 is disposed between at least portions of component 30and at least portions of connection posts 67. The dielectric substrate88 can also form a component tether 52 (or portion thereof) and extendonto or form a part of anchor 50. A component tether 52 can also beconstructed using an encapsulation layer or a structure or layer ofcomponent 30 for example.

Referring still to FIGS. 46A and 46B, component 30 is formed overdielectric substrate 88, optionally with the use of a seed layer, and isdisposed entirely over sacrificial portion 82. A via is formed throughdielectric substrate 88 and component electrodes 61 patterned toelectrically connect component 30 to connection posts 67 throughdielectric substrate 88, with component top electrodes 60 (as shown inFIG. 46A) or component bottom electrodes 62 (as shown in FIG. 46B), orboth. Component electrodes 61 can be evaporated and patterned metaltraces or wires. Dielectric substrate 88 can be patterned andsacrificial portions 82 etched to suspend component 30 over asacrificial gap 84 (e.g., as shown in FIG. 30) so that component 30 canbe micro-transfer printed, fracturing component tether 52 to formfractured component tether 53, for example micro-transfer printingcomponent 30 onto a patterned layer of adhesive 16 or a drop of adhesive16 on patterned substrate 10. Adhesive 16 can be disposed in contactwith connection posts 67 and optionally in contact with only a portionof component bottom side 39 or dielectric substrate 88, for examplelimited to the region of connection posts 67, avoiding areas ofcomponent bottom side 39 or dielectric substrate 88 distant fromconnection posts 67. In some embodiments, by micro-transfer printingcomponent 30 with connection posts 67 directly to electrodes 66 onpatterned substrate 10, subsequent photolithographic processing can beavoided, improving manufacturing efficiency. Only portions of components30 are adhered to patterned substrate 10 so that non-adhered component30 portions can move freely, enabling improved component mechanicalresonance. Components 30 with connection posts 67 have been constructedand successfully micro-transfer printed, electrically connected, andoperated.

FIG. 47 illustrates an acoustic wave transducer 94 comprising componenttop electrode 60, component bottom electrode 62 (obscured in FIG. 47),and component 30, where component top electrode 60 and component bottomelectrode 61 can form resonant acoustic waves in component 30. Componenttop electrode 60 extends onto dielectric substrate 88 and iselectrically connected to a connection post 67 (obscured in FIG. 47 butas shown in FIG. 46A). FIG. 48 illustrates two acoustic wave transducers94 comprising component top electrodes 60 and component 30, whereelectrodes 60 can form surface acoustic waves in component 30. Componenttop electrodes 60 extend onto dielectric substrate 88 and areelectrically connected to connection posts 67 (obscured in FIG. 48 butas shown in FIG. 46B). (Component 30 is a portion of both acoustic wavetransducers 94 shown in FIG. 48.) In either case, dielectric substrate88 can be in contact with substantially all of component bottom side 39(e.g., as shown in FIG. 17B) or dielectric substrate 88 can be presentonly in the local region of connection posts 67 (as shown in FIGS. 47,48, for example under component 30 for less than or equal to one half,one third, one quarter, one fifth, or one eighth of the component 30length, or is closer to the component center 32 than to an end ofcomponent 30) so that component 30 can vibrate more readily and withfewer mechanical constraints. Dielectric substrate 88 can be shaped orstructured by photolithographic processes such as etching, for exampleby undercutting component 30 (shown in FIG. 36I). In some embodiments,both or either bulk or surface acoustic wave resonant modes are presentin a component 30 and substrate post 12 configuration. In someembodiments, both or either bulk or surface acoustic wave resonant modesare present in a component 30 and dielectric substrate 88 configuration.Thus, component 30 can be a portion of a surface acoustic wavetransducer 94 (e.g., along with one or more component electrodes 61) ora portion of a bulk acoustic wave transducer 94 (e.g., along with one ormore component electrodes 61). In some embodiments, a printed orprintable structure 99 includes a bulk or surface acoustic wave filteror a bulk or surface acoustic wave sensor that includes an acoustic wavetransducer 94 (and optionally a second acoustic wave transducer 94).

In some embodiments, and as shown in FIG. 48, a component 30 can bedisposed on two or more substrate posts 12 and can extend over an edgeof each substrate post 12. Referring to FIGS. 49A-49F, according to someembodiments, micro-transfer printable components 30 with top and bottomcomponent electrodes 60, 62 can be constructed on a component sourcewafer 40 by providing component source wafer 40 with a sacrificial layer81 comprising sacrificial portions 82 adjacent to one or more anchors 50(shown in FIG. 49A), disposing and patterning component bottom electrode62 at least partially on or, in some embodiments, completely onsacrificial layer 82 (shown in FIG. 49B), disposing and patterningcomponent 30 on or over component bottom electrode 62 (shown in FIG.49C), disposing and patterning component top electrode 60 on or overcomponent 30 (shown in FIG. 49D), and disposing and patterningencapsulation layer 79 on or over component top electrode 60 toencapsulate component 30 and form component tethers 52 (shown in FIG.49E). Sacrificial portion 82 can be etched to form gap 84 and releasecomponent 30 from component source substrate 40 so that component 30(with top and bottom component electrodes 60, 62 and encapsulation layer79) can be micro-transfer printed (shown in FIG. 49F).

According to some embodiments of the present disclosure and asillustrated in FIGS. 50A and 50B, a printed structure 99 comprises apatterned substrate 10 comprising a substrate surface 11 and a substratepost 12 protruding from the substrate surface 11. The substrate post 12comprises a substrate post material that is an adhesive 16. A component30 has a component top side 38 and a component bottom side 39 oppositecomponent top side 38. Component bottom side 39 is disposed on substratepost 12 and extends over at least one edge of substrate post 12.Component 30 can comprise or have an attached broken (e.g., fractured)or separated component tether 53, for example as a consequence ofmicro-transfer printing component 30 onto substrate post 12.

As illustrated in FIG. 50A, adhesive 16 can be deposited as a drop, forexample from an inkjet printer. In some embodiments, and as illustratedin FIG. 50B, adhesive 16 can be deposited as a layer and then patterned,for example by photolithographic processing. In some embodiments, forexample where substrate post 12 is inkjet printed orphotolithographically patterned, patterned substrate 10 can comprise aplurality of substrate posts 12 disposed in an adhesive 16 layer onsubstrate 10 and forming the pattern of the patterned substrate 10.

Adhesive 16 of substrate post 12 can be a curable or cured adhesive 16.Adhesive 16 of substrate post 12 can be an uncured adhesive 16 that issubsequently cured. Uncured adhesive 16 can be an uncured adhesive 16that is deposited on substrate surface 11 of substrate 10 as a liquid,for example by laminating, coating, or spraying adhesive 16 ontosubstrate surface 11 of substrate 10. Adhesive 16 can be a soft-curedadhesive 16, for example an adhesive 16 from which at least some, amajority, or a substantial majority of solvents or other volatilematerials are evaporated or otherwise removed or driven out from uncuredadhesive 16 that is still relatively malleable, compliant, orconformable compared to a hard-cured adhesive 16 and can be shaped orotherwise deformed by pressing against the soft-cured adhesive 16, forexample with a component 30. An uncured or soft-cured adhesive 16 can behard cured by, for example, by heating or exposure to electromagneticradiation that renders adhesive 16 a cured, relatively rigid,non-compliant, non-conformable, and solid adhesive 16 with substantiallyreduced stickiness or adhesion compared to uncured or soft-curedadhesive 16. Thus, in some embodiments, adhesive 16 can be completelyuncured, soft-cured, or hard-cured at various stages of constructingprinted structures 99 of the present disclosure. A layer of soft-cured(e.g., partially cured) adhesive 16 can be patterned, for example byphotolithographic processing using masks to expose the layer of uncuredadhesive 16 and removing either the exposed or unexposed adhesive 16 toform a patterned layer of soft-cured adhesive 16 on substrate 10 andrendering substrate 10 a patterned substrate 10.

According to embodiments of the present disclosure, adhesive 16 cancomprise an organic material, a polymer, a resin, or an epoxy. Accordingto some embodiments, adhesive 16 is a photoresist. According to someembodiments, adhesive 16 is a positive photoresist. As is well known inthe photolithographic arts, a positive photoresist is a photoresistthat, when disposed on a substrate (e.g., substrate 10) and exposed toappropriate illumination (e.g., ultra-violet, infrared, or visiblelight), at least partially breaks down and can be washed away.Therefore, a patterned exposure (e.g., through a mask) and washing of alayer of positive photoresist will remove portions of the layer that areexposed and portions of the layer that are not exposed are left inplace, for example on substrate 10. Thus, masked exposure of a layer ofpositive photoresist to radiation will chemically transform the exposedportions of the layer so it can be washed away and will not chemicallyprocess the unexposed portions of the layer that remains on substrate10, so that the soft-cured positive photoresist will largely maintainits adhesive properties.

In contrast, a negative photoresist, when disposed on a substrate andexposed to appropriate illumination (e.g., ultra-violet, infrared, orvisible light) is solidified and cannot be easily washed away.Therefore, a patterned exposure (e.g., through a mask) and washing of alayer of negative photoresist will remove portions of the layer that arenot exposed and portions of the layer that are exposed are left inplace, the opposite response to masked exposure of a positivephotoresist. Thus, masked exposure of a layer of negative photoresist toradiation will chemically transform the exposed portions of the layerthat remain in place without chemically processing the unexposedportions of the layer that can be washed away. The chemicaltransformation of the exposed portions of negative photoresist canrender the exposed portion less adhesive.

Accordingly, the portion of a layer of positive photoresist layer thatremains on substrate 10 after patterning is not chemically processed andtherefore remains relatively deformable, compliant, conformable, andsticky (adhesive), as in its soft-cured state. In contrast, the portionof a negative photoresist layer that remains on substrate 10 afterpatterning is chemically processed and rendered much more solid,inflexible, and less adhesive. Therefore, patterned positive photoresistis more adhesive, compliant, and conformable than patterned negativephotoresist and component 30 can be micro-transfer printed onto asubstrate post 12 comprising a patterned positive photoresist adhesive16 much more effectively than component 30 can be micro-transfer printedonto a substrate post 12 comprising a patterned negative photoresist.After micro-transfer printing component 30 onto patterned positivephotoresist adhesive 16, patterned positive photoresist adhesive 16 canbe cured (e.g., hard cured with heat or radiation) to robustly affixcomponent 30 to substrate post 12 (cured patterned positive photoresistadhesive 16).

Components 30 micro-transfer printed onto substrate post 12 on substrate10 can be electrically connected to conductors or other electricaldevices disposed on substrate 10. As shown in FIGS. 22A-23D, forexample, components 30 are electrically connected to substrateelectrodes 66 with component electrodes 61 (e.g., component top andbottom electrodes 60, 62). In some embodiments, electrical connectionsbetween components 30 and substrate electrodes 66 are made withconnection posts 67 that are electrically connected to componentcircuits 34 and extend from components 30, for example as shown in FIGS.40-45. When components 30 are disposed on substrate posts 12, substrateposts 12 can have a height that is comparable to the height ofconnection posts 67, for example equal to or slightly less than theheight of connection posts 67, e.g., within 5%, 10%, 15%, 20%, or 25% ofthe height of connection posts 67 extending from component 30. Whensubstrate posts 12 have a height that is slightly less than the heightof connection posts 67, either before or after curing patterned adhesive16 making up substrate posts 12, connection posts 67 can make contactwith substrate contact pads disposed on substrate 10 (e.g., make contactwith substrate electrodes 66), as shown in FIGS. 5A and 50B. In someembodiments, connection posts 67 can be in contact with substrateelectrodes 66 after micro-transfer printing component 30 to patternedadhesive 16 substrate posts 12, for example in contact with, extendinto, or pierce substrate electrodes 66, but before curing adhesive 16.In some embodiments, connection posts 67 can be in contact withsubstrate electrodes 66 after micro-transfer printing component 30 topatterned adhesive 16 substrate posts 12, for example in contact with,extend into, or pierce substrate electrodes 66, after curing adhesive16. The cure process for adhesive 16 can shrink adhesive 16, for exampleby 10%-25% or by 15%-20%, pulling component 30 closer to and in morerobust contact with substrate 10 and pulling connection posts 67 intofirmer physical and electrical contact with substrate electrodes 66 sothat component 30 is held in compression against substrate 10 andcomponent 30 is held in electrical contact with substrate electrodes 66through connection posts 67. Thus, providing (e.g., hard-cured)substrate posts 12 having a height equal to or less than a height ofconnection posts 67 can enable or improve an electrical connectionbetween component 30 (e.g., connection post 67) and substrate electrodes66 on substrate 10. In some embodiments, substrate post 12 has a heightgreater than or equal to a height of connection posts 67 when uncured orsoft-cured and subsequently a smaller height that is less than or equalto a height of connection posts 67 after hard curing.

According to some embodiments of the present disclosure, electricalconnections between connection posts 67 and substrate electrodes 66 areenhanced by ensuring that adhesive 16 between component 30 and substrate10 is disposed only between connection posts 67 on substrate 10 and isnot in contact with connection posts 67, e.g., none of adhesive 16 isdisposed on substrate electrodes 66. Thus, when connection posts 67 arepressed onto and into substrate electrodes 66, there is no adhesive 16present to obstruct or interfere with an electrical connection betweenconnection posts 67 and substrate electrodes 66, improving theelectrical connection between connection posts 67 and substrateelectrodes 66.

According to some embodiments of the present disclosure and asillustrated in FIG. 50B, solder 68 can be disposed on substrateelectrodes 66. Solder 68 can coat substrate electrodes 66 and can coatconnection posts 67, for example after heating solder 68 to reflowsolder 68 so that solder 68 wicks along a surface of substrateelectrodes 66 and connection posts 67 in contact with solder 68. Solder68 can be reflowed in a common step with hard-curing patterned adhesive16 to cure substrate posts 12 so that an electrical connection betweenconnection posts 67 and substrate electrodes 66 is created, enabled, orenhanced.

In some embodiments of the present disclosure, component 30 comprises abroken (e.g., fractured) or separated component tether 53, for exampleas a consequence of micro-transfer printing component 30 from acomponent source wafer 40 to substrate post 12 of substrate 10.

As illustrated in the flow diagram of FIG. 51 and the successive crosssections of FIGS. 52A-52I, according to embodiments of the presentdisclosure a method of making a printed structure 99 comprises providinga component source wafer 40 comprising components 30 in step 100 andproviding a transfer device (e.g., a stamp 20) in step 110. In step 120a patterned substrate 10 can be provided by first providing a substrate10 in step 121 and as shown in FIG. 52A, forming substrate electrodes 66on substrate 10, for example using photolithographic methods andmaterials, as shown in FIG. 52B, disposing a layer of adhesive 16 onsubstrate 10 as a liquid adhesive 16A in step 300 as shown in FIG. 52C,soft curing adhesive 16 to disperse any solvents in liquid adhesive 16Aand solidify liquid adhesive 16A forming soft-cured adhesive 16B, forexample by drying or heating with a low heat (for example a heat that isnot greater than 120, 110, 100, or 90 degrees C.) in step 310 and asshown in FIG. 52D, and patterning the layer of soft-cured adhesive 16Bto form substrate posts 12 that extend from and pattern a surface ofsubstrate 10 in step 320 and as shown in FIG. 52E. Adhesive 16 can be apositive photoresist, for example AZ1505 or AZ10XT from MicrochemicalsGmbH. Patterned substrate 10 can be provided in step 120 usingphotolithographic materials and methods known in the art.

In step 130, stamp 20 can be moved to component source wafer 40 and canpick up components 30 from component source wafer 40 in step 140 byadhering components 30 to stamp 20. Stamp 20 with components 30 can bemoved to patterned substrate 10 with substrate posts 12 in step 150 asshown in FIG. 52F. One or more of picked-up components 30 can be printedto patterned substrate 10 substrate posts 12 in step 160 by disposingeach of the one or more picked-up components 30 onto one of substrateposts 12 as shown in FIG. 52G, thereby providing one or more printedcomponents 30 in a printed structure 99, as shown in FIG. 52H with stamp20 removed. In FIG. 52H, component 30 is a distance S1 from a surface ofpatterned substrate 10, for example a height of soft-cured adhesive 16Bsubstrate post 12. In step 330, patterned soft-cured adhesive 16B ishard cured forming hard-cured adhesive 16C substrate posts 12 as shownin FIG. 52I, for example by exposing substrate posts 12 to a temperaturegreater than 120 degrees C., for example no less than 130, 140, 145, or150 degrees C. Hard curing substrate posts 12 comprising patternedsoft-cured adhesive 16B can shrink substrate posts 12 and patternedsoft-cured adhesive 16B, pulling components 30 in compression againstpatterned substrate 10 and reflow any solder 68. In FIG. 52I, component30 is a distance S2 less than S1 (for example 5%, 10%, 15%, 10%, or 25%less) from patterned substrate 10, for example a height of hard-curedadhesive 16C substrate post 12.

Thus, methods of the present disclosure comprise soft curing adhesive 16layer in step 310, patterning adhesive 16 layer to form substrate posts12 in step 320, printing each picked-up component 30 onto substrateposts 12 in step 160, and hard curing patterned adhesive 16 layer andsubstrate posts 12 in step 330. Hard curing substrate posts 12 in step330 can also reflow a solder 68 disposed on substrate electrodes 66 (orconnection posts 67, or both) onto substrate electrodes 66 andconnection posts 67 to improve electrical connections between connectionposts 67 and substrate electrodes 66. After heating and reflowing solder68 and hard curing substrate posts 12, printed structure 99 can becooled and put into service.

As shown in FIGS. 52D and 52E, soft-cured adhesive layer 16B can bephotolithographically patterned by providing a mask, exposing soft-curedadhesive 16B with a pattern, and removing the exposed soft-curedadhesive 16B to form substrate posts 12. This method requires a mask toprovide the pattern. In some embodiments of the present disclosure andas shown in FIGS. 53A-53F, substrate electrodes 66 (substrate contactpads 66) are used as a mask and unpatterned soft-cured adhesive 16B isexposed through substrate 10 to pattern soft-cured adhesive 16B. Forexample, substrate 10 can be at least 50%, at least 60%, at least 70%,at least 80%, at least 90%, or at least 95% transparent to at least onewavelength of electromagnetic radiation that is also able to breakdown(or in some embodiments cure) adhesive 16B.

FIG. 53A illustrates substrate 10 with substrate contact pads 66 and anunpatterned soft-cured adhesive layer 16B. (FIG. 53A corresponds to FIG.52D.) Unpatterned soft-cured adhesive layer 16B is pattern-wise exposedthrough substrate 10 with electromagnetic radiation 28 and masked withsubstrate contact pads 66 so that unexposed portions of soft-curedadhesive layer 16B become broken down adhesive 16D and can be washed orrinsed away, as shown in FIG. 53C. In some such embodiments, theadhesive layer 16 can be a negative photoresist. Once soft-curedadhesive layer 16B is patterned, component 30 can be printed ontosubstrate 10 and onto remaining soft-cured adhesive layer 16B, as shownin FIG. 53D, soft-cured adhesive layer 16B can be hard cured to formhard-cured adhesive 16C as shown in FIG. 53E, and any undesirablehard-cured adhesive 16C (not under component 30) can be removed, asshown in FIG. 53F, for example by exposure to a reactive gas, such as anoxygen plasma. The step of hard curing can pull component 30 closer incompression to substrate 10 and more firmly electrically connectconnection posts 67 with substrate contact pads 16.

As noted above, the remaining portion of a negative photoresist afterpatterned exposure is chemically processed by the patterned exposure andthe chemical processing can alter the attributes of the remainingmaterial. Hence, the benefit of using a negative photoresist with aself-aligned mask (e.g., exposed through substrate contact pads 66) foradhesive layer 16 can be compared to the benefit of using a positivephotoresist with an additional mask in any practical application.

According to embodiments of the present disclosure, when component 30 isprinted onto substrate posts 12 (patterned soft-cured adhesive layer16B), the soft-cured adhesive changes its shape and can bulge outwardfrom its original position and can, for example, come into contact withsubstrate contact pads 66. If the volume of soft-cured adhesive 16B istoo large, soft-cured adhesive 16B can come into contact with (e.g.,between) substrate contact pads 66 and connection posts 67 and inhibitan electrical contact between substrate contact pads 66 and connectionposts 67. This undesirable consequence can be avoided by reducing thevolume of soft-cured adhesive 16B on substrate 10 (while still enablingcontact with component 30 during printing) and disposing soft-curedadhesive 16B sufficiently far from connection posts 67. In the processdisclosed in FIGS. 53A-53F, this can be achieved by disposing largersubstrate contact pads 66 closer together than connection posts 67. FIG.53D illustrates a separation distance D1 between substrate contact pads66 on substrate 10 that is less than a separation distance D2 betweenconnection posts 67 of component 30. This configuration is applicable toboth positive and negative photoresist adhesive layers 16.

Furthermore, under pressure from component 30, soft-cured adhesive layer16B can be pressed onto and over a portion of substrate contact pads 66,but without coming between connection posts 67 and substrate contactpads 66, e.g., as shown in FIGS. 53D-53F. In some embodiments and asshown in FIGS. 53D-53F, connection posts 67 have a substantially planaror flat distal end (the end farthest away from component 30) and leavingat least some portions of substrate contact pads 66 (substrateelectrodes 66) free from adhesive layer 16 (and free from substrateposts 12) can enhance the electrical connection between substratecontact pads 66 and connection posts 67. To help prevent patternedadhesive layer 66 from undesirably coating too much of substrate contactpads 66, according to some such embodiments, the area of a cross sectionof substrate post 12 between component 30 and substrate 10 is less thanan area of a cross section bounded by component 30, substrate post 12,and connection posts 67.

According to some embodiments of the present disclosure, connectionposts 67 are component contact pads 67 with a substantially flat surfacethat is in contact with substrate electrodes 66 (e.g., substrate contactpads 66). Because, in such embodiments, component contact pads 67 andsubstrate contact pads 66 have an extended electrical contact area(e.g., connection posts 67 do not have a sharp point), it is desirablethat no adhesive is present in the electrical contact area because suchadhesive can inhibit a good electrical connection. Thus, as shown inFIGS. 54A-54C, according to some embodiments of the present disclosure,a printed structure 99 comprises a patterned substrate 10 comprising asubstrate surface 11 and a substrate post 12 protruding from substratesurface 11. Substrate post 12 can comprise a substrate post materialthat is an adhesive. In some embodiments, the adhesive is an onlypartially cured adhesive; in some embodiments the adhesive is a curedadhesive. A component 30 has a component top side 38 and a componentbottom side 39 opposite component top side 38. Component bottom side 39is disposed on substrate post 12 and extends over at least one edge ofsubstrate post 12. One or more component contact pads 67 (e.g.,substantially planar connection posts 67) are disposed on bottom side 39and can be, for example, connected to an electrical circuit in component30, for example a CMOS circuit. In some embodiments, substrateelectrodes 66 are disposed on patterned substrate 10 adjacent tosubstrate post 12 and each of the one or more component contact pads 67is in electrical contact with one of substrate electrodes 66.

As shown in the embodiments of FIG. 54A, hard-cured adhesive 16C (orsoft-cured adhesive 16B) is disposed between component 30 and patternedsubstrate 10. Hard-cured adhesive 16C (or soft-cured adhesive 16B) formssubstrate post 12. None of hard-cured adhesive 16C (or soft-curedadhesive 16B) is in contact with either component contact pad 67 orsubstrate contact pad 66 and component contact pad 67 and substratecontact pad 66 have an extended electrical contact area without anyintervening adhesive between substrate contact pad 66 and componentcontact pad 67.

As shown in the embodiments of FIG. 54B, component contact pads 67 arecloser together than substrate contact pads 66. In some embodiments,hard-cured adhesive 16C (or soft-cured adhesive 16B) is in contact withonly a portion of component contact pads 67 but not substrate contactpads 66 so that component contact pad 67 and substrate contact pad 66have an extended electrical contact area without any interveningadhesive between substrate contact pad 66 and component contact pad 67.

In some embodiments and as illustrated in FIG. 54C, substrate contactpads 66 are closer together than component contact pads 67. In someembodiments, hard-cured adhesive 16C (or soft-cured adhesive 16B) is incontact with only a portion of substrate contact pads 66 but notcomponent contact pads 67 so that component contact pad 67 and substratecontact pad 66 have an extended electrical contact area without anyintervening adhesive between substrate contact pad 66 and componentcontact pad 67. The embodiment of FIG. 54C enables substrate contactpads 66 to form a mask when patterning adhesive to form substrate posts12, as shown in FIG. 53B.

Substrate contact pads 66 and component contact pads 67 can be easier toconstruct than electrical contacts that extend away from substratesurface 11 or component 30 (e.g., have a sharp point) and can provide agreater electrical contact area that improves the electricalconductivity between component 30 and substrate electrodes 66, therebyimproving the electrical performance of printed structure 99.

According to some embodiments, electrical connection between connectionposts 67 and substrate electrodes 66 are enhanced by a non-directionalmetal deposition such as by chemical vapor, electroless plating, orelectroplating. In some embodiments, substrate contact pads 66(substrate electrodes 66) on patterned substrate 10 can be wave solderedafter hard curing to form or improve an electrical connection betweensubstrate electrodes 66 and connection posts 67. Exposed hard-curedadhesive 16C can be removed for example by a reactive plasma or organicmaterial dry etch, such as an oxygen plasma.

In some conventional practices, a soft-cured adhesive is soft cured byexposure to elevated temperatures (e.g., greater than room temperaturebut less than a hard-cure temperature) or to radiation. In someembodiments, lengthy exposure to room temperature or ambient temperaturecan also soft cure adhesive layer 16.

Examples of micro-transfer printing processes suitable for disposingcomponents 30 onto patterned substrates 10 are described in Inorganiclight-emitting diode displays using micro-transfer printing (Journal ofthe Society for Information Display, 2017, DOI #10.1002/jsid.610,1071-0922/17/2510-0610, pages 589-609), U.S. Pat. No. 8,722,458 entitledOptical Systems Fabricated by Printing-Based Assembly, U.S. patentapplication Ser. No. 15/461,703 entitled Pressure Activated ElectricalInterconnection by Micro-Transfer Printing, U.S. Pat. No. 8,889,485entitled Methods for Surface Attachment of Flipped Active Components,U.S. patent application Ser. No. 14/822,864 entitled Chiplets withConnection Posts, U.S. patent application Ser. No. 14/743,788 entitledMicro-Assembled LED Displays and Lighting Elements, and U.S. patentapplication Ser. No. 15/373,865, entitled Micro-Transfer Printable LEDComponent, the disclosure of each of which is incorporated herein byreference in its entirety. Examples of micro-transfer printed acousticwave filter devices are described in U.S. patent application Ser. No.15/047,250, entitled Micro-Transfer Printed Acoustic Wave Filter Device,the disclosure of which is incorporated herein by reference in itsentirety.

For a discussion of various micro-transfer printing techniques, see alsoU.S. Pat. Nos. 7,622,367 and 8,506,867, each of which is herebyincorporated by reference in its entirety. Micro-transfer printing usingcompound micro-assembly structures and methods can also be used incertain embodiments, for example, as described in U.S. patentapplication Ser. No. 14/822,868, filed Aug. 10, 2015, entitled CompoundMicro-Assembly Strategies and Devices, which is hereby also incorporatedby reference in its entirety. In some embodiments, any one or more ofcomponent 30, module 98, printed structure 99 (e.g., including anacoustic wave transducer 94) is a compound micro-assembled structure(e.g., a compound micro-assembled macro-system).

According to various embodiments, component source wafer 40 can beprovided with components 30, patterned sacrificial portions 82,component tethers 52, and anchors 50 already formed, or they can beconstructed as part of a method in accordance with certain embodiments.Component source wafer 40 and components 30, micro-transfer printingdevice (e.g., a stamp 20), and patterned substrate 10 can be madeseparately and at different times or in different temporal orders orlocations and provided in various process states.

The spatial distribution of any one or more of components 30, modules98, and printed or printable structures 99 is a matter of design choicefor the end product desired. In some embodiments, all components 30 inan array on a component source wafer 40 are transferred to a transferdevice 20. In some embodiments, a subset of components 30 in an array ona component source wafer 40 is transferred. By varying the number andarrangement of stamp posts 22 on transfer stamps 20, the distribution ofcomponents 30 on stamp posts 22 of the transfer stamp 20 can be likewisevaried, as can the distribution of components 30 on patterned substrate10.

Because components 30, in certain embodiments, can be made usingintegrated circuit photolithographic techniques having a relatively highresolution and cost and patterned substrate 10, for example a printedcircuit board, can be made using printed circuit board techniques havinga relatively low resolution and cost, electrical conductors (e.g.,substrate post electrodes 64) and substrate electrodes 66 on patternedsubstrate 10 can be much larger than electrical contacts or componentelectrodes 61 on component 30, thereby reducing manufacturing costs. Forexample, in certain embodiments, micro-transfer printable component 30has at least one of a width, length, and height from 0.5 μm to 200 μm(e.g., 0.5 to 2 μm, 2 to 5 μm, 5 to 10 μm, 10 to 20 μm, 20 to 50 μm, or50 to 100 μm, or 100 to 200 μm).

In certain embodiments, patterned substrate 10 is or comprises a memberselected from the group consisting of polymer (e.g., plastic, polyimide,PEN, or PET), resin, metal (e.g., metal foil) glass, a semiconductor,and sapphire. In certain embodiments, a patterned substrate 10 has athickness from 5 microns to 20 mm (e.g., 5 to 10 microns, 10 to 50microns, 50 to 100 microns, 100 to 200 microns, 200 to 500 microns, 500microns to 0.5 mm, 0.5 to 1 mm, 1 mm to 5 mm, 5 mm to 10 mm, or 10 mm to20 mm).

Components 30, in certain embodiments, can be constructed using foundryfabrication processes used in the art. Layers of materials can be used,including materials such as metals, oxides, nitrides and other materialsused in the integrated-circuit art. Each component 30 can be or includea complete semiconductor integrated circuit and can include, forexample, any combination of one or more of a transistor, a diode, alight-emitting diode, and a sensor. Components 30 can have differentsizes, for example, at least 100 square microns, at least 1,000 squaremicrons, at least 10,000 square microns, at least 100,000 squaremicrons, or at least 1 square mm. Alternatively or additionally,components 30 can be no more than 100 square microns, no more than 1,000square microns, no more than 10,000 square microns, no more than 100,000square microns, or no more than 1 square mm, for example. Components 30can have variable aspect ratios, for example between 1:1 and 10:1 (e.g.,1:1, 2:1, 5:1, or 10:1). Components 30 can be rectangular or can haveother shapes, such as polygonal or circular shapes for example.

Various embodiments of structures and methods were described herein.Structures and methods were variously described as transferringcomponents 30, printing components 30, or micro-transferring components30. Micro-transfer-printing involves using a transfer device (e.g., anelastomeric stamp 20, such as a PDMS stamp 20) to transfer a component30 using controlled adhesion. For example, an exemplary transfer devicecan use kinetic or shear-assisted control of adhesion between a transferdevice and a component 30. It is contemplated that, in certainembodiments, where a method is described as includingmicro-transfer-printing a component 30, other analogous embodimentsexist using a different transfer method. As used herein, transferring acomponent 30 (e.g., from a component source substrate or wafer 40 to adestination patterned substrate 10) can be accomplished using any one ormore of a variety of known techniques. For example, in certainembodiments, a pick-and-place method can be used. As another example, incertain embodiments, a flip-chip method can be used (e.g., involving anintermediate, handle or carrier substrate). In methods according tocertain embodiments, a vacuum tool or other transfer device is used totransfer a component 30. As is understood by those skilled in the art,the terms “over” and “under” are relative terms and can be interchangedin reference to different orientations of the layers, elements, andsubstrates included in various embodiments of the present disclosure.Furthermore, a first layer or first element “on” a second layer orsecond element, respectively, is a relative orientation of the firstlayer or first element to the second layer or second element,respectively, that does not preclude additional layers being disposedtherebetween. For example, a first layer on a second layer, in someimplementations, means a first layer directly on and in contact with asecond layer. In other implementations, a first layer on a second layerincludes a first layer and a second layer with another layertherebetween (e.g., and in mutual contact). In some embodiments, acomponent 30 has connection posts 67 extending therefrom and is disposed“on” a substrate 10 or a substrate post 12 with connection posts 67disposed between substrate 10 or substrate post 12 and component 30.

Having described certain implementations of embodiments, it will nowbecome apparent to one of skill in the art that other implementationsincorporating the concepts of the disclosure may be used. Therefore, thedisclosure should not be limited to certain implementations, but rathershould be limited only by the spirit and scope of the following claims.

Throughout the description, where apparatus and systems are described ashaving, including, or comprising specific elements, or where processesand methods are described as having, including, or comprising specificsteps, it is contemplated that, additionally, there are apparatus andsystems of the disclosed technology that consist essentially of, orconsist of, the recited elements, and that there are processes andmethods according to the disclosed technology that consist essentiallyof, or consist of, the recited processing steps.

It should be understood that the order of steps or order for performingcertain action is immaterial so long as the disclosed technology remainsoperable. Moreover, two or more steps or actions in some circumstancescan be conducted simultaneously. The disclosure has been described indetail with particular reference to certain embodiments thereof, but itwill be understood that variations and modifications can be effectedwithin the spirit and scope of the following claims.

PARTS LIST

-   A cross secti1on line-   D1 separation distance-   D2 separation distance-   L length-   W width-   10 substrate/patterned substrate-   11 substrate surface-   12 substrate post-   14 substrate post separation distance-   16 adhesive/adhesive layer-   16A liquid adhesive-   16B soft-cured adhesive-   16C hard-cured adhesive-   16D broken-down adhesive/washable adhesive-   17 carrier substrate-   18 substrate post area-   19 substrate post top side-   20 transfer device/stamp-   22 stamp post-   24 stamp component separation distance-   26 stamp post area-   28 radiation-   30 component-   30P substrate post component-   30S stamp component-   32 component center-   34 component circuit-   36 component area-   38 component top side-   39 component bottom side-   40 component source wafer/substrate-   44 dielectric layer-   46 simple closed curve-   50 anchor-   52 component tether-   53 broken component tether-   56 cavity layer-   57 post layer-   58 component layer-   60 component top electrode-   61 component electrode-   62 component bottom electrode-   64 substrate post electrode-   66 substrate electrode/substrate contact pad-   67 connection post/component contact pad-   68 solder-   69 wire bond-   70 cavity-   72 cavity floor-   74 cavity wall-   76 cap-   78 broken cap tether-   79 encapsulation layer-   80 module source wafer-   81 sacrificial layer-   82 sacrificial portion-   84 sacrificial gap-   86 etch-stop layer-   88 dielectric substrate-   90 substrate circuit-   92 module tether-   94 acoustic wave transducer-   98 module structure/module-   99 printed structure/printable structure-   100 provide component source wafer step-   110 provide stamp step-   120 provide patterned substrate step-   121 provide substrate step-   130 move stamp to component source wafer step-   140 pick up components from component source wafer with stamp step-   150 move stamp to patterned substrate location step-   151 move stamp to substrate location step-   160 print components to patterned substrate with stamp step-   161 print components to substrate with stamp step-   170 done step-   180 complete step-   200 provide patterned substrate with substrate post step-   202 provide patterned substrate with substrate post and walls step-   206 provide substrate step-   210 dispose component step-   212 micro-transfer print component from component source wafer step-   214 form component step-   216 optional form etch mask step-   218 form cavity with substrate post and walls step-   220 dispose cap step-   222 micro-transfer print cap with walls step-   224 form walls step-   225 micro-transfer print or laminate cap step-   226 micro-transfer print module step-   227 pick up module with pick-up stamp step-   228 transfer module to print stamp step-   229 print module with print stamp step-   230 optional encapsulate module step-   240 optional micro-transfer print module from module substrate step

1. A printed structure, comprising: a patterned substrate comprising asubstrate surface and a substrate post protruding from the substratesurface, the substrate post comprising a substrate post material that isan only partially cured adhesive; and a component having a component topside and a component bottom side opposite the component top side, thecomponent bottom side disposed on the substrate post and extending overat least one edge of the substrate post.
 2. The printed structure ofclaim 1, wherein the adhesive is a soft-cured adhesive.
 3. The printedstructure of claim 1, wherein the adhesive comprises an organicmaterial, a polymer, a resin, or an epoxy.
 4. The printed structure ofclaim 1, wherein the adhesive is a photoresist.
 5. The printed structureof claim 6, wherein the photoresist is a positive photoresist. 6.(canceled)
 7. The printed structure of claim 1, comprising one or moreconnection posts extending from the component toward the patternedsubstrate.
 8. The printed structure of claim 7, comprising substrateelectrodes disposed on the patterned substrate adjacent to the substratepost and wherein each of the one or more connection posts is inelectrical contact with one of the substrate electrodes.
 9. The printedstructure of claim 8, (i) wherein the adhesive between the component andthe substrate is disposed only between the substrate electrodes and isnot in contact with the substrate electrodes, (ii) wherein none of theadhesive is disposed on the substrate electrodes, (iii) wherein adhesiveis disposed on only a portion of the substrate electrodes but not on theone or more connection posts, (iv) wherein adhesive is disposed on onlya portion of the one or more connection posts but not on the substrateelectrodes, or (v) any combination of (i), (ii), (iii), and (iv). 10.(canceled)
 11. The printed structure of claim 8, wherein only a portionof the substrate post is disposed on only a portion of the substrateelectrodes.
 12. The printed structure of claim 8, wherein the connectionposts extend into or penetrate the substrate electrodes to make anelectrical contact between the component and the substrate electrodes.13. The printed structure of claim 8, wherein an area of a cross sectionof the substrate post between the component and the substrate is lessthan an area of a cross section bounded by the component, the substrate,and the substrate electrodes.
 14. The printed structure of claim 8,wherein the substrate electrodes are closer together than any portion ofthe one or more connection posts or wherein the one or more connectionposts are closer together than any portion of the substrate electrodes.15. The printed structure of claim 7, (i) wherein the adhesive betweenthe component and the substrate is disposed only between the one or moreconnection posts and is not in contact with the one or more connectionposts, (ii) wherein none of the adhesive is disposed on the one or moreconnection posts, or (iii) both (i) and (ii).
 16. The printed structureof claim 7, wherein the one or more connection posts have asubstantially flat distal end or wherein the one or more connectionposts are each a substantially planar component contact pad.
 17. Theprinted structure of claim 7, wherein a height of the one or moreconnection posts is greater than or equal to the height of the substratepost.
 18. (canceled)
 19. The printed structure of claim 7, wherein thearea of a cross section of the substrate post between the component andthe substrate is less than an area of a cross section bounded by thecomponent, the substrate, and the one or more connection posts. 20.(canceled)
 21. The printed structure of claim 1, wherein the componentcomprises a broken or separated component tether.
 22. (canceled)
 23. Theprinted structure of claim 1, wherein the substrate post holds thecomponent in compression against the substrate. 24-38. (canceled)
 39. Aprinted structure, comprising: a patterned substrate comprising asubstrate surface and a substrate post protruding from the substratesurface, the substrate post comprising a substrate post material that isan adhesive; a component having a component top side and a componentbottom side opposite the component top side, the component bottom sidedisposed on the substrate post and extending over at least one edge ofthe substrate post; and one or more component contact pads disposed onthe bottom side.
 40. The printed structure of claim 39, comprisingsubstrate electrodes disposed on the patterned substrate adjacent to thesubstrate post and wherein each of the one or more component contactpads is in electrical contact with one of the substrate electrodes.